where type is either the word 'from' or 'rcpt'. sender and recipient can be the actual sender, recipient, a wildcard or a regular expression (uses regex(3))
The accesslist happens at SMTP and mails which get restricted get rejected with permanent 5xx code.
To give some examples
rcpt:email@example.com:firstname.lastname@example.org rcpt:email@example.com:firstname.lastname@example.org from:email@example.com:firstname.lastname@example.org
The above accesslist implies that only the users with email email@example.com and firstname.lastname@example.org can send a mail to the email email@example.com
The 3rd line implies that all outside mails from the sender firstname.lastname@example.org will be rejected at SMTP unless the recipi…