This page refers to Mailserver version 4.6 and options are slightly different from the same function in Mailserver 4.5 simple filtering
Sometimes it's convenient to filter email into different mailboxes directly and the Mailserver Project has a simple and effective way of accomplishing this by utilizing email address extensions. It works like this:
In this example Monty Burns that has the email address burns@springfield.com and has the following mailboxes in his mailfolder:
He can then automatically get email into the “money” mailbox by using the address burns+money@springfield.com when he for instance subscribe to the Financial Times email announcements.
To get email into the “guarddogs” mailbox in the folder “maillists” he would use the address burns+maillists.guarddogs@springfield.com.
For this to work, the mailboxes cannot contain spaces and needs to be in lower case.
Also, if you enter an extension that does not exist, i.e. burns+bogus@springfield.com without there being a mailbox called bogus the mail will be saved to your Inbox.