[FEATURE] Send-only accounts
I would like to use my email server for sending non-personal, domain related emails (for instance, allow Monit on other servers to send notifications via monit@example.com). I can just add a new user (monit@example.com) with credentials that should allow other servers to use my mail server as a relay, but it would be nice to restrict those accounts to just sending (ie, no receiving, no message storage, etc.), similar to how many companies have no-reply@example.com accounts.
It looks like this should be possible with postfix's check_recipient_access
option, as in https://serverfault.com/questions/856305/postfix-dovecot-create-send-only-email-account#856366, and this will even return a message to the sender for why the email was rejected.
I'm thinking this could be a simple send-only
option in the loginAccounts
set for that user. Does anyone have any other thoughts on how this should be implemented, or which features should be supported?