Mobile users can't send mail through Postfix on my XServe.

October 2, 2007 3:33 PM

XServe Postfix: How can I disable hostname verification so that mobile users can send mail successfully through my server?

One of our mail users cannot send messages through our server from her BlackJack phone. Checking the SMTP logs, I see lots of this:

Oct 2 18:15:11 rammserve postfix/smtpd[12253]: warning: 32.161.215.131: hostname mobile-032-161-215-131.mycingular.net verification failed: Host not found

Googling indicates that this is because the hostname has no PTR record. Nothing I can do about that, so I'm looking to disable this check. It's apparently due to the reject_unknown_client_hostname configuration directive, and/or something in smtpd_helo_restrictions.

However, I can't find where any of this stuff is enabled on the server. It's a default configuration XServe. I've looked over the output from postconf -d, but can't find anything that's causing this warning. Where else should I look? Is this even the problem? If not, what else?

posted by odinsdream to computers & internet (6 comments total)

'postconf -d' outputs the default configuration for postfix, not what's actually set on your server. Run postconf by itself.
posted by marionnette en chaussette at 3:58 PM on October 2, 2007

Ah. I've updated the above link to show the output of postconf. Thanks.
posted by odinsdream at 4:22 PM on October 2, 2007

I don't have an answer for you, but I do have a warning: make sure you don't turn your server into an open mail relay, to be found by and abused by spammers.
posted by Steven C. Den Beste at 6:06 PM on October 2, 2007 [1 favorite]

It's been a while, but if I recall correctly the warning you're seeing will show up whether the mail is rejected or not. Is there another entry in the log about the rejection? Or a bounce sent to the user?
posted by dreadpiratesully at 6:19 PM on October 2, 2007

Don't accept mail on port 25. Use port 587, aka 'submission'. It's for submitting mail to mail servers by authenticated external clients.

Add to master.cf:

587 inet n - n - 12   smtpd -o smtpd_enforce_tls=yes -o smtpd_sasl_auth_enable=yes

in main.cf under "smtpd_sender_restrictions" you want to have "permit_sasl_authenticated" listed before "reject_unknown_client_hostname". This will mean that any mail sent by clients using authentication will be accepted.

You'll need to get sasl auth working, docs are here if you don't already have that.
posted by Jerub at 6:52 PM on October 2, 2007

dreadpiratesully, nope, no bounce was sent. The user reports that an error message is presented on her phone soon after she clicks send. This is the only message that shows up in the logs, so I was hoping I was on to something.
posted by odinsdream at 8:38 PM on October 2, 2007