Exim filter files include an &%if%& command with its own regular expression
matching condition.
+.new
+.vitem "&$acl_arg1$&, &$acl_arg2$&, etc"
+Within an acl condition, expansion condition or expansion item
+any arguments are copied to these variables,
+any unused variables being made empty.
+.wen
+
.vitem "&$acl_c...$&"
Values can be placed in these variables by the &%set%& modifier in an ACL. They
can be given any name that starts with &$acl_c$& and is at least six characters
and can be accessed by filters, routers, and transports during subsequent
delivery.
+.new
+.vitem &$acl_narg$&
+Within an acl condition, expansion condition or expansion item
+this variable has the number of arguments.
+.wen
+
.vitem &$acl_verify_message$&
.vindex "&$acl_verify_message$&"
After an address verification has failed, this variable contains the failure
.scindex IIDdcotauth2 "authenticators" "&(dovecot)&"
This authenticator is an interface to the authentication facility of the
Dovecot POP/IMAP server, which can support a number of authentication methods.
+.new
+Note that Dovecot must be configured to use auth-client not auth-userdb.
+.wen
If you are using Dovecot to authenticate POP/IMAP clients, it might be helpful
to use the same mechanisms for SMTP authentication. This is a server
authenticator only. There is only one option: