Sending emails with postfix on centos

NotionCommotion · 03-20-2014, 12:05 PM

I am trying to set up a very simple email server, and will just need to send emails. I followed http://www.techotopia.com/index.php/...x_Email_Server. When sending an email, /var/log/maillog shows the below error. The server is physical and located in my house, and uses my Comcast modem to connect to the Internet.

Any suggestions? Thank you

EDIT I think the first problem was a result of iptables. I have it temporarily disabled, but now I get the following:

Code:

Mar 20 04:14:16 desktop postfix/pickup[11163]: B95715260BE1: uid=495 from=<gitlab@localhost>
Mar 20 04:14:16 desktop postfix/cleanup[12682]: B95715260BE1: message-id=<532acd8885983_2fe43faa55e97ed0627c3@desktop.mysite.com.mail>
Mar 20 04:14:16 desktop postfix/qmgr[11164]: B95715260BE1: from=<gitlab@localhost.mysite.com>, size=696, nrcpt=1 (queue active)
Mar 20 04:14:16 desktop postfix/smtp[12684]: connect to mx2.comcast.net[2001:558:fe2d:70::22]:25: Network is unreachable
Mar 20 04:14:16 desktop postfix/smtp[12684]: connect to mx1.comcast.net[2001:558:fe14:70::22]:25: Network is unreachable
Mar 20 04:14:46 desktop postfix/smtp[12684]: connect to mx2.comcast.net[yy.yy.yy.yyy]:25: Connection timed out
Mar 20 04:15:16 desktop postfix/smtp[12684]: connect to mx1.comcast.net[xx.xx.xx.xxx]:25: Connection timed out
Mar 20 04:15:17 desktop postfix/smtp[12684]: B95715260BE1: to=<dummy@comcast.net>, relay=none, delay=60, delays=0.24/0.01/60/0, dsn=4.4.1, status=deferred (connect to mx1.comcast.net[xx.xx.xx.xxx]:25: Connection timed out)

EDIT. This was my original log, but I think I experienced the problems due to iptables.

Code:

Mar 20 03:59:15 desktop postfix/pickup[11163]: 6EFB75260BDD: uid=495 from=<gitlab@localhost>
Mar 20 03:59:15 desktop postfix/cleanup[12378]: 6EFB75260BDD: message-id=<532aca0342c35_2fe43faa55e97ed0626fa@desktop.mysite.com.mail>
Mar 20 03:59:15 desktop postfix/qmgr[11164]: 6EFB75260BDD: from=<gitlab@localhost.mysite.com>, size=696, nrcpt=1 (queue active)
Mar 20 03:59:15 desktop postfix/error[12380]: 6EFB75260BDD: to=<dummy@comcast.net>, relay=none, delay=0.19, delays=0.09/0.01/0/0.09, dsn=4.4.1, status=deferred (delivery temporarily suspended: connect to mx1.comcast.net[xx.xx.xx.xxx]:25: Connection timed out)

NotionCommotion · 03-20-2014, 04:13 PM

Hi,

Does anyone have any ideas?

Maybe another question is why postfix is trying to use comcast.net. Yes, my Internet provider is comcast, but I don't remember editing a Linux configuration file and putting that in (but then again, I might have an forgotten!).

Please provide any suggestions how I could troubleshoot this.

Thank you

NotionCommotion · 03-20-2014, 06:46 PM

Actually, it appears to have nothing to do with comcast. I sent an email to a gmail account, and now I see google and not comcast.

Note that I tried to show only responses in /var/log/maillog that pertain to the last email sent, but I think there might be a few stranglers from earlier emails.

Please provide any clues.

Code:

Mar 20 10:41:09 desktop postfix/qmgr[3279]: B01CB5260BE9: from=<gitlab@localhost.mysite.com>, size=697, nrcpt=1 (queue active)
Mar 20 10:41:09 desktop postfix/qmgr[3279]: 161965260BE5: from=<gitlab@localhost.mysite.com>, size=701, nrcpt=1 (queue active)
Mar 20 10:41:09 desktop postfix/smtp[6424]: connect to gmail-smtp-in.l.google.com[2607:f8b0:400e:c01::1b]:25: Network is unreachable
Mar 20 10:41:27 desktop postfix/pickup[5639]: 376C55260BBF: uid=495 from=<gitlab@localhost>
Mar 20 10:41:27 desktop postfix/cleanup[6430]: 376C55260BBF: message-id=<532b2847196a4_d293f982ac74280819d2@desktop.mysite.com.mail>
Mar 20 10:41:27 desktop postfix/qmgr[3279]: 376C55260BBF: from=<gitlab@localhost.mysite.com>, size=697, nrcpt=1 (queue active)
Mar 20 10:41:27 desktop postfix/smtp[6433]: connect to gmail-smtp-in.l.google.com[2607:f8b0:400e:c01::1a]:25: Network is unreachable
Mar 20 10:41:39 desktop postfix/smtp[6425]: connect to mail.dummy.com[xx.xxx.xxx.xxx]:25: Connection timed out
Mar 20 10:41:39 desktop postfix/smtp[6425]: 161965260BE5: to=<michael@dummy.com>, relay=none, delay=1482, delays=1451/0.01/30/0, dsn=4.4.1, status=deferred (connect to mail.dummy.com[xx.xxx.xxx.xxx]:25: Connection timed out)
Mar 20 10:41:39 desktop postfix/smtp[6424]: connect to gmail-smtp-in.l.google.com[zzz.zzz.zz.zz]:25: Connection timed out
Mar 20 10:41:39 desktop postfix/smtp[6424]: connect to alt1.gmail-smtp-in.l.google.com[2607:f8b0:4001:c05::1b]:25: Network is unreachable
Mar 20 10:41:57 desktop postfix/smtp[6433]: connect to gmail-smtp-in.l.google.com[zzz.zzz.zz.zz]:25: Connection timed out
Mar 20 10:41:57 desktop postfix/smtp[6433]: connect to alt1.gmail-smtp-in.l.google.com[2607:f8b0:4001:c05::1b]:25: Network is unreachable
Mar 20 10:42:09 desktop postfix/smtp[6424]: connect to alt1.gmail-smtp-in.l.google.com[yy.yyy.yyy.yy]:25: Connection timed out
Mar 20 10:42:09 desktop postfix/smtp[6424]: connect to alt2.gmail-smtp-in.l.google.com[2607:f8b0:4002:c07::1a]:25: Network is unreachable
Mar 20 10:42:09 desktop postfix/smtp[6424]: B01CB5260BE9: to=<dummy@gmail.com>, relay=none, delay=1132, delays=1072/0.01/60/0, dsn=4.4.1, status=deferred (connect to alt2.gmail-smtp-in.l.google.com[2607:f8b0:4002:c07::1a]:25: Network is unreachable)
Mar 20 10:42:27 desktop postfix/smtp[6433]: connect to alt1.gmail-smtp-in.l.google.com[yy.yyy.yyy.yy]:25: Connection timed out
Mar 20 10:42:27 desktop postfix/smtp[6433]: connect to alt2.gmail-smtp-in.l.google.com[2607:f8b0:4002:c07::1a]:25: Network is unreachable
Mar 20 10:42:27 desktop postfix/smtp[6433]: 376C55260BBF: to=<dummy@gmail.com>, relay=none, delay=60, delays=0.14/0.01/60/0, dsn=4.4.1, status=deferred (connect to alt2.gmail-smtp-in.l.google.com[2607:f8b0:4002:c07::1a]:25: Network is unreachable)

NotionCommotion · 03-20-2014, 07:09 PM

I have a hardware firewall between my Comcast modem and my PC, Centos server, etc. Since it is only outgoing, this could not be the problem, right?

NotionCommotion · 03-20-2014, 10:12 PM

Plese?

Habitual · 03-21-2014, 01:27 PM

Most of those are network timeouts and not indicative of a postfix configuration issue.
Have you done anything to iptables? Maybe you blocked a port you shouldn't have?

Code:

iptables -L -n

will show those rules, if any exist.

you can further test your connectivity issue(s) by a few simple methods:

Code:

telnet mailhost 25
ping <mail_host_ip>

and a good "tool" I use to examine what's going on is

Code:

sendmail -v -q

Have a gander at http://www.postfix.org/SOHO_README.html

I wish I could be more helpful.

Edit: NO mailserver I know of will accept "gitlab@localhost"
See myhostname and mydomain at http://wiki.centos.org/HowTos/postfi...4db84812c8dbfd