I am running Courier 0.39.1 on RH 7.3, we are only accepting mail for one local domain (eg. localhost.com). Current using the default courier "catch all" by placing my email/user in this file /etc/courier/aliasdir/.courier-default . This has had the effect I wanted, ie any email sent not going to anything legit goes to me so dfs...@localhost.com will go to me even when there is no user dfsfa and the sender never gets back a "unknown" response. The problems is that with SO much spam it is hard for me to keep up with misspelled emails and such, to make things a little easier would there be any way to keep this catch-all but also send a "unknown recipient" response to the send? (that way senders that are smart enough will just resend with correction)