Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

My postfix configuration allows mail via several local_recipient_maps. However, delivery to "proxy:unix:passwd.byname" is specifically disabled. This normally prevents delivery to local unix users:

$ getent passwd | grep www-data
www-data:x:33:33:www-data:/var/www:/bin/sh
$ nc localhost 25
220 my.mail.host ESMTP Postfix
helo localhost
250 my.mail.host
mail from:www-data@my.mail.host
250 2.1.0 Ok
rcpt to:www-data@my.mail.host
550 5.1.1 <www-data@my.mail.host>: Recipient address rejected: User unknown in local recipient table
rcpt to:www-data
550 5.1.1 <www-data>: Recipient address rejected: User unknown in local recipient table

However this morning I noticed an email delivered to the local www-data mail spool file. Looking within, I see that:

  • it was a message from www-data@my.mail.host, sent by a different host within our network, using my.mail.host as the smarthost
  • it remained within my.mail.host queue for several days while attempting retries
  • it then bounced
  • the bounce was delivered to a "www-data" mail spool file on my.mail.host

So my question is: why did this happen, and how do I prevent it from happening in the future?

share|improve this question

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.