Postfix send mail problem(In RH9, kernal 2.4.20, postfix 2.1.5)
I install a Postfix system for our users to send out e-mail from internal network to internet/outside and usually is working fine. But I got some bounce mail in sometimes, it's look like are as follow :
This is the Postfix program at host smtp01.domain.com.
I'm sorry to have to inform you that your message could not be
be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to <postmaster>
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The Postfix program
<email@example.com>: host gmail-smtp-in.l.google.com[220.127.116.11] said: 250
2.1.5 OK (in reply to DATA command)
And I found the record on maillog are as follow :
Jul 7 19:21:55 smtp01 postfix/smtpd: warning: dict_nis_init: NIS domain name not set - NIS lookups disabled
Jul 7 19:21:55 smtp01 postfix/smtpd: connect from unknown[192.168.1.19]
Jul 7 19:21:55 smtp01 postfix/smtpd: 38415149683: client=unknown[192.168.1.19]
Jul 7 19:21:55 smtp01 postfix/cleanup: 38415149683: message-id=<firstname.lastname@example.org>
Jul 7 19:21:55 smtp01 postfix/qmgr: 38415149683: from=<email@example.com>, size=619, nrcpt=1 (queue active)
Jul 7 19:21:55 smtp01 postfix/smtpd: disconnect from unknown[192.168.1.19]
Jul 7 19:21:58 smtp01 postfix/smtp: 38415149683: to=<firstname.lastname@example.org>, relay=gmail-smtp-in.l.google.com[18.104.22.168], delay=3, status=sent (250 2.0.0 OK 1120730678 4si7774192rnz)
Jul 7 19:21:58 smtp01 postfix/qmgr: 38415149683: removed
What happening on my smtp server(postfix)? And we have a firewall (Cisco PIX 515E) in front of smtp server(postfix), is it a firewall problem to cause the problem? Or our internet line problem? I'm really no idea on this case, I really need your reply!!! Many thanks!