-- Actually these regular expressions were obtained from SpamAssassin project, so they are licensed by apache license: -- -- Licensed to the Apache Software Foundation (ASF) under one or more -- contributor license agreements. See the NOTICE file distributed with -- this work for additional information regarding copyright ownership. -- The ASF licenses this file to you under the Apache License, Version 2.0 -- (the "License"); you may not use this file except in compliance with -- the License. You may obtain a copy of the License at: -- -- http://www.apache.org/licenses/LICENSE-2.0 -- -- Unless required by applicable law or agreed to in writing, software -- distributed under the License is distributed on an "AS IS" BASIS, -- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -- See the License for the specific language governing permissions and -- limitations under the License. -- -- Definitions of header regexps local reconf = config['regexp'] -- Subject needs encoding -- Define encodings types local subject_encoded_b64 = 'Subject=/=\\?\\S+\\?B\\?/iX' local subject_encoded_qp = 'Subject=/=\\?\\S+\\?Q\\?/iX' -- Define whether subject must be encoded (contains non-7bit characters) local subject_needs_mime = 'Subject=/[\\x00-\\x08\\x0b\\x0c\\x0e-\\x1f\\x7f-\\xff]/X' -- Final rule reconf['SUBJECT_NEEDS_ENCODING'] = string.format('!(%s) & !(%s) & (%s)', subject_encoded_b64, subject_encoded_qp, subject_needs_mime) -- Detects that there is no space in From header (e.g. Some Name) reconf['R_NO_SPACE_IN_FROM'] = 'From=/\\S<[-\\w\\.]+\\@[-\\w\\.]+>/X' -- Detects missing subject local has_subject = 'header_exists(Subject)' local empty_subject = 'Subject=/^$/' -- Final rule reconf['MISSING_SUBJECT'] = string.format('!(%s) | (%s)', has_subject, empty_subject) -- Detects bad content-transfer-encoding for text parts -- For text parts (text/plain and text/html mainly) local r_ctype_text = 'content_type_is_type(text)' -- Content transfer encoding is 7bit local r_cte_7bit = 'compare_transfer_encoding(7bit)' -- And body contains 8bit characters local r_body_8bit = '/[^\\x01-\\x7f]/Pr' reconf['R_BAD_CTE_7BIT'] = string.format('(%s) & (%s) & (%s)', r_ctype_text, r_cte_7bit, r_body_8bit) -- Detects missing To header reconf['MISSING_TO']= '!raw_header_exists(To)'; -- Detects undisclosed recipients local undisc_rcpt = 'To=/^[-.\\w]{1,64})\\"?\\s<\\k\\@/H' -- Charset is missing in message reconf['R_MISSING_CHARSET']= string.format('content_type_is_type(text) & !content_type_has_param(charset) & !%s', r_cte_7bit); -- Subject seems to be spam reconf['R_SAJDING'] = 'Subject=/\\bsajding(?:om|a)?\\b/iH' -- Messages that have only HTML part reconf['MIME_HTML_ONLY'] = 'has_only_html_part()' -- Find forged Outlook MUA -- Yahoo groups messages local yahoo_bulk = 'Received=/from \\[\\S+\\] by \\S+\\.(?:groups|scd|dcn)\\.yahoo\\.com with NNFMP/H' -- Outlook MUA local outlook_mua = 'X-Mailer=/^Microsoft Outlook\\b/H' local any_outlook_mua = 'X-Mailer=/^Microsoft Outlook\\b/H' reconf['FORGED_OUTLOOK_HTML'] = string.format('!%s & %s & %s', yahoo_bulk, outlook_mua, reconf['MIME_HTML_ONLY']) -- Recipients seems to be likely with each other (only works when recipients count is more than 5 recipients) reconf['SUSPICIOUS_RECIPS'] = 'compare_recipients_distance(0.65)' -- Recipients list seems to be sorted reconf['SORTED_RECIPS'] = 'is_recipients_sorted()' -- Spam string at the end of message to make statistics faults reconf['TRACKER_ID'] = '/^[a-z0-9]{6,24}[-_a-z0-9]{2,36}[a-z0-9]{6,24}\\s*\\z/isPr' -- From that contains encoded characters while base 64 is not needed as all symbols are 7bit -- Regexp that checks that From header is encoded with base64 (search in raw headers) local from_encoded_b64 = 'From=/\\=\\?\\S+\\?B\\?/iX' -- From contains only 7bit characters (parsed headers are used) local from_needs_mime = 'From=/[\\x00-\\x08\\x0b\\x0c\\x0e-\\x1f\\x7f-\\xff]/Hr' -- Final rule reconf['FROM_EXCESS_BASE64'] = string.format('%s & !%s', from_encoded_b64, from_needs_mime) -- From that contains encoded characters while quoted-printable is not needed as all symbols are 7bit -- Regexp that checks that From header is encoded with quoted-printable (search in raw headers) local from_encoded_qp = 'From=/\\=\\?\\S+\\?Q\\?/iX' -- Final rule reconf['FROM_EXCESS_QP'] = string.format('%s & !%s', from_encoded_qp, from_needs_mime) -- To that contains encoded characters while base 64 is not needed as all symbols are 7bit -- Regexp that checks that To header is encoded with base64 (search in raw headers) local to_encoded_b64 = 'To=/\\=\\?\\S+\\?B\\?/iX' -- To contains only 7bit characters (parsed headers are used) local to_needs_mime = 'To=/[\\x00-\\x08\\x0b\\x0c\\x0e-\\x1f\\x7f-\\xff]/Hr' -- Final rule reconf['TO_EXCESS_BASE64'] = string.format('%s & !%s', to_encoded_b64, to_needs_mime) -- To that contains encoded characters while quoted-printable is not needed as all symbols are 7bit -- Regexp that checks that To header is encoded with quoted-printable (search in raw headers) local to_encoded_qp = 'To=/\\=\\?\\S+\\?Q\\?/iX' -- Final rule reconf['TO_EXCESS_QP'] = string.format('%s & !%s', to_encoded_qp, to_needs_mime) -- Reply-To that contains encoded characters while base 64 is not needed as all symbols are 7bit -- Regexp that checks that Reply-To header is encoded with base64 (search in raw headers) local replyto_encoded_b64 = 'Reply-To=/\\=\\?\\S+\\?B\\?/iX' -- Reply-To contains only 7bit characters (parsed headers are used) local replyto_needs_mime = 'Reply-To=/[\\x00-\\x08\\x0b\\x0c\\x0e-\\x1f\\x7f-\\xff]/Hr' -- Final rule reconf['REPLYTO_EXCESS_BASE64'] = string.format('%s & !%s', replyto_encoded_b64, replyto_needs_mime) -- Reply-To that contains encoded characters while quoted-printable is not needed as all symbols are 7bit -- Regexp that checks that Reply-To header is encoded with quoted-printable (search in raw headers) local replyto_encoded_qp = 'Reply-To=/\\=\\?\\S+\\?Q\\?/iX' -- Final rule reconf['REPLYTO_EXCESS_QP'] = string.format('%s & !%s', replyto_encoded_qp, replyto_needs_mime) -- Cc that contains encoded characters while base 64 is not needed as all symbols are 7bit -- Regexp that checks that Cc header is encoded with base64 (search in raw headers) local cc_encoded_b64 = 'Cc=/\\=\\?\\S+\\?B\\?/iX' -- Co contains only 7bit characters (parsed headers are used) local cc_needs_mime = 'Cc=/[\\x00-\\x08\\x0b\\x0c\\x0e-\\x1f\\x7f-\\xff]/Hr' -- Final rule reconf['CC_EXCESS_BASE64'] = string.format('%s & !%s', cc_encoded_b64, cc_needs_mime) -- Cc that contains encoded characters while quoted-printable is not needed as all symbols are 7bit -- Regexp that checks that Cc header is encoded with quoted-printable (search in raw headers) local cc_encoded_qp = 'Cc=/\\=\\?\\S+\\?Q\\?/iX' -- Final rule reconf['CC_EXCESS_QP'] = string.format('%s & !%s', cc_encoded_qp, cc_needs_mime) -- Detect forged outlook headers -- OE X-Mailer header local oe_mua = 'X-Mailer=/\\bOutlook Express [456]\\./H' -- OE Message ID format local oe_msgid_1 = 'Message-Id=/^[A-Za-z0-9-]{7}[A-Za-z0-9]{20}\\@hotmail\\.com$/mH' local oe_msgid_2 = 'Message-Id=/^(?:[0-9a-f]{8}|[0-9a-f]{12})\\$[0-9a-f]{8}\\$[0-9a-f]{8}\\@\\S+$/mH' -- EZLM remail of message local lyris_ezml_remailer = 'List-Unsubscribe=/$/H' -- Header of wacky sendmail local wacky_sendmail_version = 'Received=/\\/CWT\\/DCE\\)/H' -- Iplanet received header local iplanet_messaging_server = 'Received=/iPlanet Messaging Server/H' -- Hotmail message id local hotmail_baydav_msgid = 'Message-Id=/^BAY\\d+-DAV\\d+[A-Z0-9]{25}\\@phx\\.gbl$/mH' -- Sympatico message id local sympatico_msgid = 'Message-Id=/^BAYC\\d+-PASMTP\\d+[A-Z0-9]{25}\\@CEZ\\.ICE$/mH' -- Mailman message id local mailman_msgid = 'Message-ID=/^$/XS' -- Message id seems to be forged local unusable_msgid = string.format('(%s | %s | %s | %s | %s | %s)', lyris_ezml_remailer, wacky_sendmail_version, iplanet_messaging_server, hotmail_baydav_msgid, sympatico_msgid, mailman_msgid) -- Outlook express data seems to be forged local forged_oe = string.format('(%s & !%s & !%s & !%s)', oe_mua, oe_msgid_1, oe_msgid_2, unusable_msgid) -- Outlook specific headers local outlook_dollars_mua = 'X-Mailer=/^Microsoft Outlook(?: 8| CWS, Build 9|, Build 10)\\./H' local outlook_dollars_other = 'Message-Id=/^\\!\\~\\!/mH' local vista_msgid = 'Message-Id=/^[A-F\\d]{32}\\@\\S+$/mH' local ims_msgid = 'Message-Id=/^[A-F\\d]{36,40}\\@\\S+$/mH' -- Forged outlook headers local forged_outlook_dollars = string.format('(%s & !%s & !%s & !%s & !%s & !%s', outlook_dollars_mua, oe_msgid_2, outlook_dollars_other, vista_msgid, ims_msgid, unusable_msgid) -- Outlook versions that should be excluded from summary rule local fmo_excl_o3416 = 'X-Mailer=/^Microsoft Outlook, Build 10.0.3416$/H' local fmo_excl_oe3790 = 'X-Mailer=/^Microsoft Outlook Express 6.00.3790.3959$/H' -- Summary rule for forged outlook reconf['FORGED_MUA_OUTLOOK'] = string.format('(%s | %s) & !%s & !%s & !%s', forged_oe, forged_outlook_dollars, fmo_excl_o3416, fmo_excl_oe3790, vista_msgid) -- HTML outlook signs local mime_html = 'content_type_is_type(text) & content_type_is_subtype(/.?html/)' local tag_exists_html = 'has_html_tag(html)' local tag_exists_head = 'has_html_tag(head)' local tag_exists_meta = 'has_html_tag(meta)' local tag_exists_body = 'has_html_tag(body)' reconf['FORGED_OUTLOOK_TAGS'] = string.format('!%s & %s & %s & !(%s & %s & %s & %s)', yahoo_bulk, any_outlook_mua, mime_html, tag_exists_html, tag_exists_head, tag_exists_meta, tag_exists_body) -- Forged OE/MSO boundary reconf['SUSPICIOUS_BOUNDARY'] = 'Content-Type=/^\\s*multipart.+boundary="----=_NextPart_000_[A-Z\\d]{4}_(00EBFFA4|0102FFA4|32C6FFA4|3302FFA4)\\.[A-Z\\d]{8}"[\\r\\n]*$/siX' -- Forged OE/MSO boundary reconf['SUSPICIOUS_BOUNDARY2'] = 'Content-Type=/^\\s*multipart.+boundary="----=_NextPart_000_[A-Z\\d]{4}_(01C6527E)\\.[A-Z\\d]{8}"[\\r\\n]*$/siX' -- Forged OE/MSO boundary reconf['SUSPICIOUS_BOUNDARY3'] = 'Content-Type=/^\\s*multipart.+boundary="-----000-00\\d\\d-01C[\\dA-F]{5}-[\\dA-F]{8}"[\\r\\n]*$/siX' -- Forged OE/MSO boundary local suspicious_boundary_01C4 = 'Content-Type=/^\\s*multipart.+boundary="----=_NextPart_000_[A-Z\\d]{4}_01C4[\\dA-F]{4}\\.[A-Z\\d]{8}"[\\r\\n]*$/siX' local suspicious_boundary_01C4_date = 'Date=/^\\s*\\w\\w\\w,\\s+\\d+\\s+\\w\\w\\w 20(0[56789]|1\\d)/' reconf['SUSPICIOUS_BOUNDARY4'] = string.format('(%s) & (%s)', suspicious_boundary_01C4, suspicious_boundary_01C4_date) -- Detect forged The Bat! headers -- The Bat! X-Mailer header local thebat_mua_any = 'X-Mailer=/^\\s*The Bat!/H' -- The Bat! common Message-ID template local thebat_msgid_common = 'Message-ID=/^\\d+\\.\\d+\\@\\S+$/mH' -- Correct The Bat! Message-ID template local thebat_msgid = 'Message-ID=/^\\d+\\.(19[789]\\d|20\\d\\d)(0\\d|1[012])([012]\\d|3[01])([0-5]\\d)([0-5]\\d)([0-5]\\d)\\@\\S+/mH' -- Summary rule for forged The Bat! Message-ID header reconf['FORGED_MUA_THEBAT_MSGID'] = string.format('(%s) & !(%s) & (%s) & !(%s)', thebat_mua_any, thebat_msgid, thebat_msgid_common, unusable_msgid) -- Summary rule for forged The Bat! Message-ID header with unknown template reconf['FORGED_MUA_THEBAT_MSGID_UNKNOWN'] = string.format('(%s) & !(%s) & !(%s) & !(%s)', thebat_mua_any, thebat_msgid, thebat_msgid_common, unusable_msgid) -- Detect forged KMail headers -- KMail User-Agent header local kmail_mua = 'User-Agent=/^\\s*KMail\\/1\\.\\d+\\.\\d+/H' -- KMail common Message-ID template local kmail_msgid_common = 'Message-Id=/^\\s*\\d+\\.\\d+\\.\\S+\\@\\S+$/mH' function kmail_msgid (task) local msg = task:get_message() local regexp_text = '<(\\S+)>\\|(19[789]\\d|20\\d\\d)(0\\d|1[012])([012]\\d|3[01])([0-5]\\d)([0-5]\\d)\\.\\d+\\.\\1$' local re = regexp.get_cached(regexp_text) if not re then re = regexp.create(regexp_text, '') end local header_msgid = msg:get_header('Message-Id') if header_msgid then for _,header_from in ipairs(msg:get_header('From')) do if re:match(header_from.."|"..header_msgid[1]) then return true end end end return false end -- Summary rule for forged KMail Message-ID header reconf['FORGED_MUA_KMAIL_MSGID'] = string.format('(%s) & (%s) & !(%s) & !(%s)', kmail_mua, kmail_msgid_common, 'kmail_msgid', unusable_msgid) -- Summary rule for forged KMail Message-ID header with unknown template reconf['FORGED_MUA_KMAIL_MSGID_UNKNOWN'] = string.format('(%s) & !(%s) & !(%s)', kmail_mua, kmail_msgid_common, unusable_msgid) -- Detect forged Opera Mail headers -- Opera Mail User-Agent header local opera1x_mua = 'User-Agent=/^\\s*Opera Mail\\/1[01]\\.\\d+ /H' -- Opera Mail Message-ID template local opera1x_msgid = 'Message-ID=/^op\\.[a-z\\d]{14}\\@\\S+$/mHS' -- Suspicious Opera Mail User-Agent header local suspicious_opera10w_mua = 'User-Agent=/^\\s*Opera Mail\\/10\\.\\d+ \\(Windows\\)$/H' -- Suspicious Opera Mail Message-ID, apparently from KMail local suspicious_opera10w_msgid = 'Message-Id=/^2009\\d{8}\\.\\d+\\.\\S+\\@\\S+$/mHS' -- Summary rule for forged Opera Mail User-Agent header and Message-ID header from KMail reconf['SUSPICIOUS_OPERA_10W_MSGID'] = string.format('(%s) & (%s)', suspicious_opera10w_mua, suspicious_opera10w_msgid) -- Summary rule for forged Opera Mail Message-ID header reconf['FORGED_MUA_OPERA_MSGID'] = string.format('(%s) & !(%s) & !(%s) & !(%s)', opera1x_mua, opera1x_msgid, reconf['SUSPICIOUS_OPERA_10W_MSGID'], unusable_msgid) -- Detect forged Mozilla Mail/Thunderbird/Seamonkey headers -- Mozilla based X-Mailer local user_agent_mozilla5 = 'User-Agent=/^\\s*Mozilla\\/5\\.0/' local user_agent_thunderbird = 'User-Agent=/^\\s*(Thunderbird|Mozilla Thunderbird|Mozilla\\/.*Gecko\\/.*Thunderbird\\/)/' local user_agent_seamonkey = 'User-Agent=/^\\s*Mozilla\\/5\\.0\\s.+\\sSeaMonkey\\/\\d+\\.\\d+/' local user_agent_mozilla = string.format('(%s) & !(%s) & !(%s)', user_agent_mozilla5, user_agent_thunderbird, user_agent_seamonkey) -- Mozilla based common Message-ID template local mozilla_msgid_common = 'Message-ID=/^\\s*<[\\dA-F]{8}\\.\\d{1,7}\\@([^>\\.]+\\.)+[^>\\.]+>$/X' local mozilla_msgid = 'Message-ID=/^\\s*<(3[3-9A-F]|4[\\dA-F]|5[\\dA-F])[\\dA-F]{6}\\.(\\d0){0,3}\\d\\@([^>\\.]+\\.)+[^>\\.]+>$/XS' -- Summary rule for forged Mozilla Mail Message-ID header reconf['FORGED_MUA_MOZILLA_MAIL_MSGID'] = string.format('(%s) & (%s) & !(%s) & !(%s)', user_agent_mozilla, mozilla_msgid_common, mozilla_msgid, unusable_msgid) reconf['FORGED_MUA_MOZILLA_MAIL_MSGID_UNKNOWN'] = string.format('(%s) & !(%s) & !(%s) & !(%s)', user_agent_mozilla, mozilla_msgid_common, mozilla_msgid, unusable_msgid) -- Summary rule for forged Thunderbird Message-ID header reconf['FORGED_MUA_THUNDERBIRD_MSGID'] = string.format('(%s) & (%s) & !(%s) & !(%s)', user_agent_thunderbird, mozilla_msgid_common, mozilla_msgid, unusable_msgid) reconf['FORGED_MUA_THUNDERBIRD_MSGID_UNKNOWN'] = string.format('(%s) & !(%s) & !(%s) & !(%s)', user_agent_thunderbird, mozilla_msgid_common, mozilla_msgid, unusable_msgid) -- Summary rule for forged Seamonkey Message-ID header reconf['FORGED_MUA_SEAMONKEY_MSGID'] = string.format('(%s) & (%s) & !(%s) & !(%s)', user_agent_seamonkey, mozilla_msgid_common, mozilla_msgid, unusable_msgid) reconf['FORGED_MUA_SEAMONKEY_MSGID_UNKNOWN'] = string.format('(%s) & !(%s) & !(%s) & !(%s)', user_agent_seamonkey, mozilla_msgid_common, mozilla_msgid, unusable_msgid) -- Message id validity local sane_msgid = 'Message-Id=/^[^<>\\\\ \\t\\n\\r\\x0b\\x80-\\xff]+\\@[^<>\\\\ \\t\\n\\r\\x0b\\x80-\\xff]+\\s*$/mH' local msgid_comment = 'Message-Id=/\\(.*\\)/mH' reconf['INVALID_MSGID'] = string.format('(%s) & !((%s) | (%s))', has_mid, sane_msgid, msgid_comment) -- Only Content-Type header without other MIME headers local cd = 'header_exists(Content-Disposition)' local cte = 'header_exists(Content-Transfer-Encoding)' local ct = 'header_exists(Content-Type)' local mime_version = 'raw_header_exists(MIME-Version)' local ct_text_plain = 'content_type_is_type(text) & content_type_is_subtype(plain)' reconf['MIME_HEADER_CTYPE_ONLY'] = string.format('!(%s) & !(%s) & (%s) & !(%s) & !(%s)', cd, cte, ct, mime_version, ct_text_plain) -- Forged Exchange messages local msgid_dollars_ok = 'Message-Id=/[0-9a-f]{4,}\\$[0-9a-f]{4,}\\$[0-9a-f]{4,}\\@\\S+/Hr' local mimeole_ms = 'X-MimeOLE=/^Produced By Microsoft MimeOLE/H' local rcvd_with_exchange = 'Received=/with Microsoft Exchange Server/H' reconf['RATWARE_MS_HASH'] = string.format('(%s) & !(%s) & !(%s)', msgid_dollars_ok, mimeole_ms, rcvd_with_exchange) -- Reply-type in content-type reconf['STOX_REPLY_TYPE'] = 'Content-Type=/text\\/plain; .* reply-type=original/H' -- Fake Verizon headers local fhelo_verizon = 'X-Spam-Relays-Untrusted=/^[^\\]]+ helo=[^ ]+verizon\\.net /iH' local fhost_verizon = 'X-Spam-Relays-Untrusted=/^[^\\]]+ rdns=[^ ]+verizon\\.net /iH' reconf['FM_FAKE_HELO_VERIZON'] = string.format('(%s) & !(%s)', fhelo_verizon, fhost_verizon) -- Forged yahoo msgid local at_yahoo_msgid = 'Message-Id=/\\@yahoo\\.com\\b/iH' local at_yahoogroups_msgid = 'Message-Id=/\\@yahoogroups\\.com\\b/iH' local from_yahoo_com = 'From=/\\@yahoo\\.com\\b/iH' reconf['FORGED_MSGID_YAHOO'] = string.format('(%s) & !(%s)', at_yahoo_msgid, from_yahoo_com) local r_from_yahoo_groups = 'From=/rambler.ru\\@returns\\.groups\\.yahoo\\.com\\b/iH' local r_from_yahoo_groups_ro = 'From=/ro.ru\\@returns\\.groups\\.yahoo\\.com\\b/iH' -- Forged The Bat! MUA headers local thebat_mua_v1 = 'X-Mailer=/^The Bat! \\(v1\\./H' local ctype_has_boundary = 'Content-Type=/boundary/iH' local bat_boundary = 'Content-Type=/boundary=\\"?-{10}/H' local mailman_21 = 'X-Mailman-Version=/\\d/H' reconf['FORGED_MUA_THEBAT_BOUN'] = string.format('(%s) & (%s) & !(%s) & !(%s)', thebat_mua_v1, ctype_has_boundary, bat_boundary, mailman_21) -- Two received headers with ip addresses local double_ip_spam_1 = 'Received=/from \\[\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\] by \\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3} with/H' local double_ip_spam_2 = 'Received=/from\\s+\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\s+by\\s+\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3};/H' reconf['RCVD_DOUBLE_IP_SPAM'] = string.format('(%s) | (%s)', double_ip_spam_1, double_ip_spam_2) -- Quoted reply-to from yahoo (seems to be forged) local repto_quote = 'Reply-To=/\\".*\\"\\s*\\\\/\\\\,\\-:=]' local re = regexp.get_cached(regexp_text) if not re then re = regexp.create(regexp_text, 's') end if headers_recv then for _,header_to in ipairs(headers_to) do for _,header_r in ipairs(headers_recv) do if re:match(header_to.."|"..header_r['value']) then return true end end checked = checked + 1 if checked > 5 then -- Stop on 5 rcpt return false end end end end return false end rspamd_config.INVALID_EXIM_RECEIVED2 = function (task) local checked = 0 local headers_to = task:get_message():get_header('To') if headers_to then local headers_recv = task:get_raw_header('Received') local regexp_text = '^[^\\n]*??\\|.*from \\d+\\.\\d+\\.\\d+\\.\\d+ \\(HELO \\S+\\)[\\s\\r\\n]*by \\1 with esmtp \\([A-Z]{9,12} [A-Z]{5,6}\\)[\\s\\r\\n]+id [a-zA-Z\\d]{6}-[a-zA-Z\\d]{6}-[a-zA-Z\\d]{2}[\\s\\r\\n]+' local re = regexp.get_cached(regexp_text) if not re then re = regexp.create(regexp_text, 's') end if headers_recv then for _,header_to in ipairs(headers_to) do for _,header_r in ipairs(headers_recv) do if re:match(header_to.."|"..header_r['value']) then return true end end checked = checked + 1 if checked > 5 then -- Stop on 5 rcpt return false end end end end return false end