> > I see from my logs that someone has repeatedly sending > mail to a non-existent user on my system (for once this is > something I actually want, not a piece of spam) > > How should the sending smtp server react to constant > messages from my smtp server to the effect that the > message is rejected : > > Dec 16 03:40:57 www postfix/smtpd[23914]: NOQUEUE: reject: > RCPT from mta202-rme.xtra.co.nz[210.86.15.145]: 450 > <[EMAIL PROTECTED]>: Recipient address rejected: User > unknown in local recipient table; > from=<[EMAIL PROTECTED]> to=<[EMAIL PROTECTED]> > proto=ESMTP helo=<mta202-rme.xtra.co.nz> > > the sender does not seem to have got any bounce or > notification - this started on Monday, its now friday and > still going on. -- > Nick Rout <[EMAIL PROTECTED]>
FIRST: add an alias for the account they are trying to send to to an account locally, postalias, and accept the mail, if you really do want to receive it, without making the sender send it again. A 450 indicates temporary failure on the part of *your* mail server. Xtra will just keep trying to redeliver the mail until it expires or you accept it. Comment out the unknown_local_recipient_reject_code = 450 line in postfix's main.cf (which is added by postfix from a 1->2 upgrade from memory, and may be there in 2 by default), and restart postfix. Then do: [EMAIL PROTECTED] root]# postconf unknown_local_recipient_reject_code which should report back: unknown_local_recipient_reject_code = 550 This will make the sending mail server not retry if the user can't be identified. The other bonus will be Sober.I's infected hosts will get rejected after they fail their first 20 wrong mail addresses (unless you've changed smtpd_hard_error_limit). Regards Daniel
