Hello... This is my feature request... I want to add reject_sender_login_mismatch to smtpd_sender_restrictions. This is very useful thing... with this users can't fake source e-mail address (user can't send e-mail contained "mail from: <email@example.com>" which is not belonging to user). Everything is fine, when I do: [user email] = [user account] (I don't need any MySQL data -> simple SELECT '%s' ). The problem is, when I want add user aliases. When user has alias, sometimes he/she want to write using alias source, eg. account is: firstname.lastname@example.org, alias is: email@example.com. User log to SMTP by account login, and in "mail from:" he/she write: firstname.lastname@example.org. Someone who designed mail_forwarding do several bad things! 1. common data with 'alias','aliasdomain','forward','catchall' ( ok I can do 'WHERE', but type is not indexed! ) 2. use text in destination! (aaaaaa!!!) 3. and don't use index in destination This is not good, more... this is performance headshot :/ I think You should repair this Destination e-mails should be in other records, and also should be indexed. Postfix understand when query gives 2 or more rows. Types should be indexed too. By the way... I switched Courier to Dovecot in ispconfig3 and it works fine If someone are interested in config files... msg to priv.