18 files changed, 1365 insertions, 132 deletions

diff --git a/lib/public/Mail/Events/BeforeMessageSent.php b/lib/public/Mail/Events/BeforeMessageSent.php
index dea748e4044..f528bd11409 100644
--- a/lib/public/Mail/Events/BeforeMessageSent.php
+++ b/lib/public/Mail/Events/BeforeMessageSent.php
@@ -3,26 +3,8 @@
 declare(strict_types=1);
 
 /**
- * @copyright 2020 Arne Hamann <github@arne.email>
- *
- * @author Arne Hamann <kontakt+github@arne.email>
- * @author Morris Jobke <hey@morrisjobke.de>
- *
- * @license GNU AGPL version 3 or any later version
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as
- * published by the Free Software Foundation, either version 3 of the
- * License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- *
+ * SPDX-FileCopyrightText: 2020 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
  */
 namespace OCP\Mail\Events;
 
diff --git a/lib/public/Mail/Headers/AutoSubmitted.php b/lib/public/Mail/Headers/AutoSubmitted.php
index 45b43c7a652..1191628d401 100644
--- a/lib/public/Mail/Headers/AutoSubmitted.php
+++ b/lib/public/Mail/Headers/AutoSubmitted.php
@@ -3,25 +3,8 @@
 declare(strict_types=1);
 
 /**
- * @copyright Copyright (c) 2022 Bennet Becker <dev@bennet.cc>
- *
- * @author Bennet Becker <dev@bennet.cc>
- *
- * @license GNU AGPL version 3 or any later version
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as
- * published by the Free Software Foundation, either version 3 of the
- * License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- *
+ * SPDX-FileCopyrightText: 2022 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
  */
 namespace OCP\Mail\Headers;
 
diff --git a/lib/public/Mail/IAttachment.php b/lib/public/Mail/IAttachment.php
index 5d013dd1c45..f58a5771cc2 100644
--- a/lib/public/Mail/IAttachment.php
+++ b/lib/public/Mail/IAttachment.php
@@ -3,26 +3,8 @@
 declare(strict_types=1);
 
 /**
- * @copyright Copyright (c) 2017 Joas Schilling <coding@schilljs.com>
- *
- * @author Joas Schilling <coding@schilljs.com>
- * @author Roeland Jago Douma <roeland@famdouma.nl>
- *
- * @license GNU AGPL version 3 or any later version
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as
- * published by the Free Software Foundation, either version 3 of the
- * License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- *
+ * SPDX-FileCopyrightText: 2017 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
  */
 namespace OCP\Mail;
 
diff --git a/lib/public/Mail/IEMailTemplate.php b/lib/public/Mail/IEMailTemplate.php
index ea0fa970c9a..66379abd8ae 100644
--- a/lib/public/Mail/IEMailTemplate.php
+++ b/lib/public/Mail/IEMailTemplate.php
@@ -3,29 +3,8 @@
 declare(strict_types=1);
 
 /**
- * @copyright 2017, Morris Jobke <hey@morrisjobke.de>
- *
- * @author Brad Rubenstein <brad@wbr.tech>
- * @author Joas Schilling <coding@schilljs.com>
- * @author Lukas Reschke <lukas@statuscode.ch>
- * @author Morris Jobke <hey@morrisjobke.de>
- * @author Roeland Jago Douma <roeland@famdouma.nl>
- *
- * @license GNU AGPL version 3 or any later version
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as
- * published by the Free Software Foundation, either version 3 of the
- * License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- *
+ * SPDX-FileCopyrightText: 2017 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
  */
 namespace OCP\Mail;
 
@@ -78,7 +57,7 @@ interface IEMailTemplate {
 	 *
 	 * @param string $title
 	 * @param string|bool $plainTitle Title that is used in the plain text email
-	 *   if empty the $title is used, if false none will be used
+	 *                                if empty the $title is used, if false none will be used
 	 *
 	 * @since 12.0.0
 	 */
@@ -89,7 +68,7 @@ interface IEMailTemplate {
 	 *
 	 * @param string $text; Note: When $plainText falls back to this, HTML is automatically escaped in the HTML email
 	 * @param string|bool $plainText Text that is used in the plain text email
-	 *   if empty the $text is used, if false none will be used
+	 *                               if empty the $text is used, if false none will be used
 	 *
 	 * @since 12.0.0
 	 */
@@ -102,9 +81,9 @@ interface IEMailTemplate {
 	 * @param string $metaInfo; Note: When $plainMetaInfo falls back to this, HTML is automatically escaped in the HTML email
 	 * @param string $icon Absolute path, must be 16*16 pixels
 	 * @param string|bool $plainText Text that is used in the plain text email
-	 *   if empty the $text is used, if false none will be used
+	 *                               if empty the $text is used, if false none will be used
 	 * @param string|bool $plainMetaInfo Meta info that is used in the plain text email
-	 *   if empty the $metaInfo is used, if false none will be used
+	 *                                   if empty the $metaInfo is used, if false none will be used
 	 * @param integer plainIndent If > 0, Indent plainText by this amount.
 	 * @since 12.0.0
 	 */
@@ -130,7 +109,7 @@ interface IEMailTemplate {
 	 * @param string $text Text of button; Note: When $plainText falls back to this, HTML is automatically escaped in the HTML email
 	 * @param string $url URL of button
 	 * @param string|false $plainText Text of button in plain text version
-	 * 		if empty the $text is used, if false none will be used
+	 *                                if empty the $text is used, if false none will be used
 	 *
 	 * @since 12.0.0
 	 */
diff --git a/lib/public/Mail/IMailer.php b/lib/public/Mail/IMailer.php
index 94044f7c720..277f7863184 100644
--- a/lib/public/Mail/IMailer.php
+++ b/lib/public/Mail/IMailer.php
@@ -1,29 +1,10 @@
 <?php
 
 declare(strict_types=1);
-
 /**
- * @copyright Copyright (c) 2016, ownCloud, Inc.
- *
- * @author Joas Schilling <coding@schilljs.com>
- * @author Lukas Reschke <lukas@statuscode.ch>
- * @author Morris Jobke <hey@morrisjobke.de>
- * @author Roeland Jago Douma <roeland@famdouma.nl>
- *
- * @license AGPL-3.0
- *
- * This code is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License, version 3,
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License, version 3,
- * along with this program. If not, see <http://www.gnu.org/licenses/>
- *
+ * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-only
  */
 namespace OCP\Mail;
 
@@ -33,7 +14,7 @@ namespace OCP\Mail;
  *
  * Example usage:
  *
- * 	$mailer = \OC::$server->getMailer();
+ * 	$mailer = \OCP\Server::get(\OCP\Mail\IMailer::class);
  * 	$message = $mailer->createMessage();
  * 	$message->setSubject('Your Subject');
  * 	$message->setFrom(['cloud@domain.org' => 'Nextcloud Notifier']);
@@ -88,9 +69,9 @@ interface IMailer {
 	 *
 	 * @param IMessage $message Message to send
 	 * @return string[] Array with failed recipients. Be aware that this depends on the used mail backend and
-	 * therefore should be considered
+	 *                  therefore should be considered
 	 * @throws \Exception In case it was not possible to send the message. (for example if an invalid mail address
-	 * has been supplied.)
+	 *                    has been supplied.)
 	 * @since 8.1.0
 	 */
 	public function send(IMessage $message): array;
diff --git a/lib/public/Mail/IMessage.php b/lib/public/Mail/IMessage.php
index 79efc1e2a71..c3d1d047478 100644
--- a/lib/public/Mail/IMessage.php
+++ b/lib/public/Mail/IMessage.php
@@ -3,26 +3,8 @@
 declare(strict_types=1);
 
 /**
- * @copyright Copyright (c) 2017 Joas Schilling <coding@schilljs.com>
- *
- * @author Joas Schilling <coding@schilljs.com>
- * @author Roeland Jago Douma <roeland@famdouma.nl>
- *
- * @license GNU AGPL version 3 or any later version
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as
- * published by the Free Software Foundation, either version 3 of the
- * License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- *
+ * SPDX-FileCopyrightText: 2017 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
  */
 namespace OCP\Mail;
 
diff --git a/lib/public/Mail/Provider/Address.php b/lib/public/Mail/Provider/Address.php
new file mode 100644
index 00000000000..751fb99d930
--- /dev/null
+++ b/lib/public/Mail/Provider/Address.php
@@ -0,0 +1,85 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\Mail\Provider;
+
+/**
+ * Mail Address Object
+ *
+ * This object is used to define the address and label of a email address
+ *
+ * @since 30.0.0
+ *
+ */
+class Address implements \OCP\Mail\Provider\IAddress {
+
+	/**
+	 * initialize the mail address object
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string|null $address mail address (e.g test@example.com)
+	 * @param string|null $label mail address label/name
+	 */
+	public function __construct(
+		protected ?string $address = null,
+		protected ?string $label = null,
+	) {
+	}
+
+	/**
+	 * sets the mail address
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value mail address (e.g. test@example.com)
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setAddress(string $value): self {
+		$this->address = $value;
+		return $this;
+	}
+
+	/**
+	 * gets the mail address
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string|null returns the mail address or null if one is not set
+	 */
+	public function getAddress(): ?string {
+		return $this->address;
+	}
+
+	/**
+	 * sets the mail address label/name
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value mail address label/name
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setLabel(string $value): self {
+		$this->label = $value;
+		return $this;
+	}
+
+	/**
+	 * gets the mail address label/name
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string|null returns the mail address label/name or null if one is not set
+	 */
+	public function getLabel(): ?string {
+		return $this->label;
+	}
+
+}
diff --git a/lib/public/Mail/Provider/Attachment.php b/lib/public/Mail/Provider/Attachment.php
new file mode 100644
index 00000000000..af7340a3ccf
--- /dev/null
+++ b/lib/public/Mail/Provider/Attachment.php
@@ -0,0 +1,139 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\Mail\Provider;
+
+/**
+ * Mail Attachment Object
+ *
+ * This object is used to define the parameters of a mail attachment
+ *
+ * @since 30.0.0
+ *
+ */
+class Attachment implements \OCP\Mail\Provider\IAttachment {
+
+	/**
+	 * initialize the mail attachment object
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string|null $contents binary contents of file
+	 * @param string|null $name file name (e.g example.txt)
+	 * @param string|null $type mime type (e.g. text/plain)
+	 * @param bool $embedded embedded status of the attachment, default is false
+	 */
+	public function __construct(
+		protected ?string $contents,
+		protected ?string $name,
+		protected ?string $type,
+		protected bool $embedded = false,
+	) {
+	}
+
+	/**
+	 * sets the attachment file name
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value file name (e.g example.txt)
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setName(string $value): self {
+		$this->name = $value;
+		return $this;
+	}
+
+	/**
+	 * gets the attachment file name
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string | null returns the attachment file name or null if not set
+	 */
+	public function getName(): ?string {
+		return $this->name;
+	}
+
+	/**
+	 * sets the attachment mime type
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value mime type (e.g. text/plain)
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setType(string $value): self {
+		$this->type = $value;
+		return $this;
+	}
+
+	/**
+	 * gets the attachment mime type
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string | null returns the attachment mime type or null if not set
+	 */
+	public function getType(): ?string {
+		return $this->type;
+	}
+
+	/**
+	 * sets the attachment contents (actual data)
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value binary contents of file
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setContents(string $value): self {
+		$this->contents = $value;
+		return $this;
+	}
+
+	/**
+	 * gets the attachment contents (actual data)
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string | null returns the attachment contents or null if not set
+	 */
+	public function getContents(): ?string {
+		return $this->contents;
+	}
+
+	/**
+	 * sets the embedded status of the attachment
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param bool $value true - embedded / false - not embedded
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setEmbedded(bool $value): self {
+		$this->embedded = $value;
+		return $this;
+	}
+
+	/**
+	 * gets the embedded status of the attachment
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return bool embedded status of the attachment
+	 */
+	public function getEmbedded(): bool {
+		return $this->embedded;
+	}
+
+}
diff --git a/lib/public/Mail/Provider/Exception/Exception.php b/lib/public/Mail/Provider/Exception/Exception.php
new file mode 100644
index 00000000000..7514c72a869
--- /dev/null
+++ b/lib/public/Mail/Provider/Exception/Exception.php
@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\Mail\Provider\Exception;
+
+/**
+ * Mail Provider Base Exception
+ *
+ * @since 30.0.0
+ */
+class Exception extends \Exception {
+
+}
diff --git a/lib/public/Mail/Provider/Exception/SendException.php b/lib/public/Mail/Provider/Exception/SendException.php
new file mode 100644
index 00000000000..fba0903cbb3
--- /dev/null
+++ b/lib/public/Mail/Provider/Exception/SendException.php
@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\Mail\Provider\Exception;
+
+/**
+ * Mail Provider Send Exception
+ *
+ * @since 30.0.0
+ */
+class SendException extends Exception {
+
+}
diff --git a/lib/public/Mail/Provider/IAddress.php b/lib/public/Mail/Provider/IAddress.php
new file mode 100644
index 00000000000..47bb9148968
--- /dev/null
+++ b/lib/public/Mail/Provider/IAddress.php
@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\Mail\Provider;
+
+/**
+ * Mail Address Interface
+ *
+ * This interface is a base requirement of methods and functionality used to construct a mail address object
+ *
+ * @since 30.0.0
+ *
+ */
+interface IAddress {
+
+	/**
+	 * sets the mail address
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value mail address (test@example.com)
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setAddress(string $value): self;
+
+	/**
+	 * gets the mail address
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string returns the mail address
+	 */
+	public function getAddress(): ?string;
+
+	/**
+	 * sets the mail address label/name
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value mail address label/name
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setLabel(string $value): self;
+
+	/**
+	 * gets the mail address label/name
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string returns the mail address label/name
+	 */
+	public function getLabel(): ?string;
+
+}
diff --git a/lib/public/Mail/Provider/IAttachment.php b/lib/public/Mail/Provider/IAttachment.php
new file mode 100644
index 00000000000..ff266994919
--- /dev/null
+++ b/lib/public/Mail/Provider/IAttachment.php
@@ -0,0 +1,101 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\Mail\Provider;
+
+/**
+ * Mail Attachment Interface
+ *
+ * This interface is used for defining individual attachments that are attached to a message
+ *
+ * @since 30.0.0
+ *
+ */
+interface IAttachment {
+
+	/**
+	 * sets the attachment file name
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value file name (e.g example.txt)
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setName(string $value): self;
+
+	/**
+	 * gets the attachment file name
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string | null returns the attachment file name or null if one is not set
+	 */
+	public function getName(): ?string;
+
+	/**
+	 * sets the attachment mime type
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value mime type (e.g. text/plain)
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setType(string $value): self;
+
+	/**
+	 * gets the attachment mime type
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string | null returns the attachment mime type or null if not set
+	 */
+	public function getType(): ?string;
+
+	/**
+	 * sets the attachment contents (actual data)
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value binary contents of file
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setContents(string $value): self;
+
+	/**
+	 * gets the attachment contents (actual data)
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string | null returns the attachment contents or null if not set
+	 */
+	public function getContents(): ?string;
+
+	/**
+	 * sets the embedded status of the attachment
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param bool $value true - embedded / false - not embedded
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setEmbedded(bool $value): self;
+
+	/**
+	 * gets the embedded status of the attachment
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return bool embedded status of the attachment
+	 */
+	public function getEmbedded(): bool;
+
+}
diff --git a/lib/public/Mail/Provider/IManager.php b/lib/public/Mail/Provider/IManager.php
new file mode 100644
index 00000000000..b55fed3f26f
--- /dev/null
+++ b/lib/public/Mail/Provider/IManager.php
@@ -0,0 +1,106 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\Mail\Provider;
+
+/**
+ * Mail Provider Manager Interface
+ *
+ * This interface is a base requirement of methods and functionality used to construct a mail provider manager object
+ *
+ * @since 30.0.0
+ *
+ */
+interface IManager {
+
+	/**
+	 * determine if any mail providers are registered
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return bool
+	 */
+	public function has(): bool;
+
+	/**
+	 * retrieve a count of how many mail providers are registered
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return int
+	 */
+	public function count(): int;
+
+	/**
+	 * retrieve which mail providers are registered
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return array<string,String> collection of provider id and label ['jmap' => 'JMap Connector']
+	 */
+	public function types(): array;
+
+	/**
+	 * retrieve all registered mail providers
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return array<string,IProvider> collection of provider id and object ['jmap' => IProviderObject]
+	 */
+	public function providers(): array;
+
+	/**
+	 * retrieve a provider with a specific id
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $providerId provider id
+	 *
+	 * @return IProvider|null
+	 */
+	public function findProviderById(string $providerId): ?IProvider;
+
+	/**
+	 * retrieve all services for all registered mail providers
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $userId user id
+	 *
+	 * @return array<string,array<string,IService>> collection of provider id, service id and object ['jmap' => ['Service1' => IServiceObject]]
+	 */
+	public function services(string $userId): array;
+
+	/**
+	 * retrieve a service with a specific id
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $userId user id
+	 * @param string $serviceId service id
+	 * @param string $providerId provider id
+	 *
+	 * @return IService|null returns service object or null if none found
+	 */
+	public function findServiceById(string $userId, string $serviceId, ?string $providerId = null): ?IService;
+
+	/**
+	 * retrieve a service for a specific mail address
+	 * returns first service with specific primary address
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $userId user id
+	 * @param string $address mail address (e.g. test@example.com)
+	 * @param string $providerId provider id
+	 *
+	 * @return IService|null returns service object or null if none found
+	 */
+	public function findServiceByAddress(string $userId, string $address, ?string $providerId = null): ?IService;
+
+}
diff --git a/lib/public/Mail/Provider/IMessage.php b/lib/public/Mail/Provider/IMessage.php
new file mode 100644
index 00000000000..599d9b0566d
--- /dev/null
+++ b/lib/public/Mail/Provider/IMessage.php
@@ -0,0 +1,232 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\Mail\Provider;
+
+/**
+ * Mail Message Interface
+ *
+ * This interface is a base requirement of methods and functionality used to construct a mail message object
+ *
+ * @since 30.0.0
+ *
+ */
+interface IMessage {
+
+	/**
+	 * arbitrary unique text string identifying this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string id of this message
+	 */
+	public function id(): string;
+
+	/**
+	 * sets the sender of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param IAddress $value sender's mail address object
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setFrom(IAddress $value): self;
+
+	/**
+	 * gets the sender of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return IAddress|null sender's mail address object
+	 */
+	public function getFrom(): ?IAddress;
+
+	/**
+	 * sets the sender's reply to address of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param IAddress $value senders's reply to mail address object
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setReplyTo(IAddress $value): self;
+
+	/**
+	 * gets the sender's reply to address of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return IAddress|null sender's reply to mail address object
+	 */
+	public function getReplyTo(): ?IAddress;
+
+	/**
+	 * sets the recipient(s) of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param IAddress ...$value collection of or one or more mail address objects
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setTo(IAddress ...$value): self;
+
+	/**
+	 * gets the recipient(s) of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return array<int,IAddress> collection of all recipient mail address objects
+	 */
+	public function getTo(): array;
+
+	/**
+	 * sets the copy to recipient(s) of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param IAddress ...$value collection of or one or more mail address objects
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setCc(IAddress ...$value): self;
+
+	/**
+	 * gets the copy to recipient(s) of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return array<int,IAddress> collection of all copied recipient mail address objects
+	 */
+	public function getCc(): array;
+
+	/**
+	 * sets the blind copy to recipient(s) of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param IAddress ...$value collection of or one or more mail address objects
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setBcc(IAddress ...$value): self;
+
+	/**
+	 * gets the blind copy to recipient(s) of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return array<int,IAddress> collection of all blind copied recipient mail address objects
+	 */
+	public function getBcc(): array;
+
+	/**
+	 * sets the subject of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value subject of mail message
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setSubject(string $value): self;
+
+	/**
+	 * gets the subject of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string|null subject of message or null if one is not set
+	 */
+	public function getSubject(): ?string;
+
+	/**
+	 * sets the plain text or html body of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value text or html body of message
+	 * @param bool $html html flag - true for html
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setBody(string $value, bool $html): self;
+
+	/**
+	 * gets either the html or plain text body of this message
+	 *
+	 * html body will be returned over plain text if html body exists
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string|null html/plain body of this message or null if one is not set
+	 */
+	public function getBody(): ?string;
+
+	/**
+	 * sets the html body of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value html body of message
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setBodyHtml(string $value): self;
+
+	/**
+	 * gets the html body of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string|null html body of this message or null if one is not set
+	 */
+	public function getBodyHtml(): ?string;
+
+	/**
+	 * sets the plain text body of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value plain text body of message
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setBodyPlain(string $value): self;
+
+	/**
+	 * gets the plain text body of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string|null plain text body of this message or null if one is not set
+	 */
+	public function getBodyPlain(): ?string;
+
+	/**
+	 * sets the attachments of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param IAttachment ...$value collection of or one or more mail attachment objects
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setAttachments(IAttachment ...$value): self;
+
+	/**
+	 * gets the attachments of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return array<int,IAttachment> collection of all mail attachment objects
+	 */
+	public function getAttachments(): array;
+}
diff --git a/lib/public/Mail/Provider/IMessageSend.php b/lib/public/Mail/Provider/IMessageSend.php
new file mode 100644
index 00000000000..fe1b2884452
--- /dev/null
+++ b/lib/public/Mail/Provider/IMessageSend.php
@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\Mail\Provider;
+
+/**
+ * Mail Message Send Interface
+ *
+ * This interface is the required set of methods and functionality used to extend IService with message sending functionality
+ *
+ * @since 30.0.0
+ *
+ */
+interface IMessageSend {
+
+	/**
+	 * send an outbound message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param IMessage $message mail message object with all required parameters to send a message
+	 * @param array $options array of options reserved for future use
+	 *
+	 * @throws \OCP\Mail\Provider\Exception\SendException on failure, check message for reason
+	 */
+	public function sendMessage(IMessage $message, array $options = []): void;
+
+}
diff --git a/lib/public/Mail/Provider/IProvider.php b/lib/public/Mail/Provider/IProvider.php
new file mode 100644
index 00000000000..d89022d7cbf
--- /dev/null
+++ b/lib/public/Mail/Provider/IProvider.php
@@ -0,0 +1,94 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\Mail\Provider;
+
+/**
+ * Mail Provider Interface
+ *
+ * This interface is a base requirement of methods and functionality used to construct a mail provider object
+ *
+ * @since 30.0.0
+ *
+ */
+interface IProvider {
+
+	/**
+	 * arbitrary unique text string identifying this provider
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string id of this provider (e.g. UUID or 'IMAP/SMTP' or anything else)
+	 */
+	public function id(): string;
+
+	/**
+	 * localized human friendly name of this provider
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string label/name of this provider (e.g. Plain Old IMAP/SMTP)
+	 */
+	public function label(): string;
+
+	/**
+	 * determine if any services are configured for a specific user
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $userId user id
+	 *
+	 * @return bool true if any services are configure for the user
+	 */
+	public function hasServices(string $userId): bool;
+
+	/**
+	 * retrieve collection of services for a specific user
+	 *
+	 * @param string $userId user id
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return array<string,IService> collection of service id and object ['1' => IServiceObject]
+	 */
+	public function listServices(string $userId): array;
+
+	/**
+	 * retrieve a service with a specific id
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $userId user id
+	 * @param string $serviceId service id
+	 *
+	 * @return IService|null returns service object or null if none found
+	 */
+	public function findServiceById(string $userId, string $serviceId): ?IService;
+
+	/**
+	 * retrieve a service for a specific mail address
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $userId user id
+	 * @param string $address mail address (e.g. test@example.com)
+	 *
+	 * @return IService|null returns service object or null if none found
+	 */
+	public function findServiceByAddress(string $userId, string $address): ?IService;
+
+	/**
+	 * construct a new empty service object
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return IService blank service object
+	 */
+	public function initiateService(): IService;
+
+}
diff --git a/lib/public/Mail/Provider/IService.php b/lib/public/Mail/Provider/IService.php
new file mode 100644
index 00000000000..e0bb5161aa6
--- /dev/null
+++ b/lib/public/Mail/Provider/IService.php
@@ -0,0 +1,119 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\Mail\Provider;
+
+/**
+ * Mail Service Interface
+ *
+ * This interface is a base requirement of methods and functionality used to construct a mail service object
+ *
+ * @since 30.0.0
+ *
+ */
+interface IService {
+
+	/**
+	 * arbitrary unique text string identifying this service
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string id of this service (e.g. 1 or service1 or anything else)
+	 */
+	public function id(): string;
+
+	/**
+	 * checks if a service is able of performing an specific action
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value required ability e.g. 'MessageSend'
+	 *
+	 * @return bool true/false if ability is supplied and found in collection
+	 */
+	public function capable(string $value): bool;
+
+	/**
+	 * retrieves a collection of what actions a service can perfrom
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return array collection of abilities otherwise empty collection
+	 */
+	public function capabilities(): array;
+
+	/**
+	 * gets the localized human frendly name of this service
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string label/name of service (e.g. ACME Company Mail Service)
+	 */
+	public function getLabel(): string;
+
+	/**
+	 * sets the localized human frendly name of this service
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value label/name of service (e.g. ACME Company Mail Service)
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setLabel(string $value): self;
+
+	/**
+	 * gets the primary mailing address for this service
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return IAddress mail address object
+	 */
+	public function getPrimaryAddress(): IAddress;
+
+	/**
+	 * sets the primary mailing address for this service
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param IAddress $value mail address object
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setPrimaryAddress(IAddress $value): self;
+
+	/**
+	 * gets the secondary mailing addresses (aliases) collection for this service
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return array<int, IAddress> collection of mail address objects
+	 */
+	public function getSecondaryAddresses(): array;
+
+	/**
+	 * sets the secondary mailing addresses (aliases) for this service
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param IAddress ...$value collection of one or more mail address objects
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setSecondaryAddresses(IAddress ...$value): self;
+
+	/**
+	 * construct a new empty message object
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return IMessage blank message object
+	 */
+	public function initiateMessage(): IMessage;
+
+}
diff --git a/lib/public/Mail/Provider/Message.php b/lib/public/Mail/Provider/Message.php
new file mode 100644
index 00000000000..f7a21c05ed3
--- /dev/null
+++ b/lib/public/Mail/Provider/Message.php
@@ -0,0 +1,338 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCP\Mail\Provider;
+
+/**
+ * Mail Message Object
+ *
+ * This object is used to define a mail message that can be used to transfer data to a provider
+ *
+ * @since 30.0.0
+ *
+ */
+class Message implements \OCP\Mail\Provider\IMessage {
+
+	/**
+	 * initialize the mail message object
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param array $data message data array
+	 */
+	public function __construct(
+		protected array $data = [],
+	) {
+	}
+
+	/**
+	 * arbitrary unique text string identifying this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string id of this message
+	 */
+	public function id(): string {
+		// return id of message
+		return (isset($this->data['id'])) ? $this->data['id'] : '';
+	}
+
+	/**
+	 * sets the sender of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param IAddress $value sender's mail address object
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setFrom(IAddress $value): self {
+		// create or update field in data store with value
+		$this->data['from'] = $value;
+		// return this object for command chaining
+		return $this;
+	}
+
+	/**
+	 * gets the sender of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return IAddress|null sender's mail address object
+	 */
+	public function getFrom(): ?IAddress {
+		// evaluate if data store field exists and return value(s) or null otherwise
+		return (isset($this->data['from'])) ? $this->data['from'] : null;
+	}
+
+	/**
+	 * sets the sender's reply to address of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param IAddress $value senders's reply to mail address object
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setReplyTo(IAddress $value): self {
+		// create or update field in data store with value
+		$this->data['replyTo'] = $value;
+		// return this object for command chaining
+		return $this;
+	}
+
+	/**
+	 * gets the sender's reply to address of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return IAddress|null sender's reply to mail address object
+	 */
+	public function getReplyTo(): ?IAddress {
+		// evaluate if data store field exists and return value(s) or null otherwise
+		return (isset($this->data['replyTo'])) ? $this->data['replyTo'] : null;
+	}
+
+	/**
+	 * sets the recipient(s) of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param IAddress ...$value collection of or one or more mail address objects
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setTo(IAddress ...$value): self {
+		// create or update field in data store with value
+		$this->data['to'] = $value;
+		// return this object for command chaining
+		return $this;
+	}
+
+	/**
+	 * gets the recipient(s) of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return array<int,IAddress> collection of all recipient mail address objects
+	 */
+	public function getTo(): array {
+		// evaluate if data store field exists and return value(s) or empty collection
+		return (isset($this->data['to'])) ? $this->data['to'] : [];
+	}
+
+	/**
+	 * sets the copy to recipient(s) of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param IAddress ...$value collection of or one or more mail address objects
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setCc(IAddress ...$value): self {
+		// create or update field in data store with value
+		$this->data['cc'] = $value;
+		// return this object for command chaining
+		return $this;
+	}
+
+	/**
+	 * gets the copy to recipient(s) of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return array<int,IAddress> collection of all copied recipient mail address objects
+	 */
+	public function getCc(): array {
+		// evaluate if data store field exists and return value(s) or empty collection
+		return (isset($this->data['cc'])) ? $this->data['cc'] : [];
+	}
+
+	/**
+	 * sets the blind copy to recipient(s) of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param IAddress ...$value collection of or one or more mail address objects
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setBcc(IAddress ...$value): self {
+		// create or update field in data store with value
+		$this->data['bcc'] = $value;
+		// return this object for command chaining
+		return $this;
+	}
+
+	/**
+	 * gets the blind copy to recipient(s) of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return array<int,IAddress> collection of all blind copied recipient mail address objects
+	 */
+	public function getBcc(): array {
+		// evaluate if data store field exists and return value(s) or empty collection
+		return (isset($this->data['bcc'])) ? $this->data['bcc'] : [];
+	}
+
+	/**
+	 * sets the subject of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value subject of mail message
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setSubject(string $value): self {
+		// create or update field in data store with value
+		$this->data['subject'] = $value;
+		// return this object for command chaining
+		return $this;
+	}
+
+	/**
+	 * gets the subject of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string|null subject of message or null if one is not set
+	 */
+	public function getSubject(): ?string {
+		// evaluate if data store field exists and return value(s) or null otherwise
+		return (isset($this->data['subject'])) ? $this->data['subject'] : null;
+	}
+
+	/**
+	 * sets the plain text or html body of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value text or html body of message
+	 * @param bool $html html flag - true for html
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setBody(string $value, bool $html = false): self {
+		// evaluate html flag and create or update appropriate field in data store with value
+		if ($html) {
+			$this->data['bodyHtml'] = $value;
+		} else {
+			$this->data['bodyPlain'] = $value;
+		}
+		// return this object for command chaining
+		return $this;
+	}
+
+	/**
+	 * gets either the html or plain text body of this message
+	 *
+	 * html body will be returned over plain text if html body exists
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string|null html/plain body of this message or null if one is not set
+	 */
+	public function getBody(): ?string {
+		// evaluate if data store field(s) exists and return value
+		if (isset($this->data['bodyHtml'])) {
+			return $this->data['bodyHtml'];
+		} elseif (isset($this->data['bodyPlain'])) {
+			return $this->data['bodyPlain'];
+		}
+		// return null if data fields did not exist in data store
+		return null;
+	}
+
+	/**
+	 * sets the html body of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value html body of message
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setBodyHtml(string $value): self {
+		// create or update field in data store with value
+		$this->data['bodyHtml'] = $value;
+		// return this object for command chaining
+		return $this;
+	}
+
+	/**
+	 * gets the html body of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string|null html body of this message or null if one is not set
+	 */
+	public function getBodyHtml(): ?string {
+		// evaluate if data store field exists and return value(s) or null otherwise
+		return (isset($this->data['bodyHtml'])) ? $this->data['bodyHtml'] : null;
+	}
+
+	/**
+	 * sets the plain text body of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param string $value plain text body of message
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setBodyPlain(string $value): self {
+		// create or update field in data store with value
+		$this->data['bodyPlain'] = $value;
+		// return this object for command chaining
+		return $this;
+	}
+
+	/**
+	 * gets the plain text body of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return string|null plain text body of this message or null if one is not set
+	 */
+	public function getBodyPlain(): ?string {
+		// evaluate if data store field exists and return value(s) or null otherwise
+		return (isset($this->data['bodyPlain'])) ? $this->data['bodyPlain'] : null;
+	}
+
+	/**
+	 * sets the attachments of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @param IAttachment ...$value collection of or one or more mail attachment objects
+	 *
+	 * @return self return this object for command chaining
+	 */
+	public function setAttachments(IAttachment ...$value): self {
+		// create or update field in data store with value
+		$this->data['attachments'] = $value;
+		// return this object for command chaining
+		return $this;
+	}
+
+	/**
+	 * gets the attachments of this message
+	 *
+	 * @since 30.0.0
+	 *
+	 * @return array<int,IAttachment> collection of all mail attachment objects
+	 */
+	public function getAttachments(): array {
+		// evaluate if data store field exists and return value(s) or null otherwise
+		return (isset($this->data['attachments'])) ? $this->data['attachments'] : [];
+	}
+
+}