[Conf] Add mx_check default config

conf/modules.d/mx_check.conf

@@ -0,0 +1,44 @@
+# Please don't modify this file as your changes might be overwritten with
+# the next update.
+#
+# You can modify '$LOCAL_CONFDIR/rspamd.conf.local.override' to redefine
+# parameters defined on the top level
+#
+# You can modify '$LOCAL_CONFDIR/rspamd.conf.local' to add
+# parameters defined on the top level
+#
+# For specific modules or configuration you can also modify
+# '$LOCAL_CONFDIR/local.d/file.conf' - to add your options or rewrite defaults
+# '$LOCAL_CONFDIR/override.d/file.conf' - to override the defaults
+#
+# See https://rspamd.com/doc/tutorials/writing_rules.html for details
+
+# This module is *DISABLED* by default
+# If you need to enable it, then define the following line in
+# local.d/mx_check.conf:
+#
+# enabled = true;
+#
+# You also need to define redis servers for this module
+
+mx_check {
+  # connection timeout in seconds
+  timeout = 1.0;
+  # symbol yielded if no MX is connectable
+  symbol_bad_mx = "MX_INVALID";
+  # symbol yielded if no MX is found
+  symbol_no_mx = "MX_MISSING";
+  # symbol yielded if MX is connectable
+  symbol_good_mx = "MX_GOOD";
+  # lifetime of redis cache - 1 day by default
+  expire = 86400;
+  # prefix used for redis key
+  key_prefix = "rmx";
+
+  # !!! Disable by default !!!
+  enabled = false;
+
+  .include(try=true,priority=5) "${DBDIR}/dynamic/mx_check.conf"
+  .include(try=true,priority=1,duplicate=merge) "$LOCAL_CONFDIR/local.d/mx_check.conf"
+  .include(try=true,priority=10) "$LOCAL_CONFDIR/override.d/mx_check.conf"
+}