Outlook Fails Send Mail When Connecting to Virtualmin and Postfix

I have just setup a new Virtualmin installation on Centos 5.x and everything seems to be working great so far except for my ability to connect to Postfix with Outlook to send mail. In Outlook 2007, pop connects successfully but after about 60 seconds, SMTP (send test email message) fails and provides the following error: Send test e-mail message: The connection to the server was interrupted. If this problem continues, contact your server administrator or Internet service provider (ISP).

This server is behind a firewall but access rules are setup for IMAP/POP/SMTP and no log messages indicating any firewall blocking. I am not sure what I am doing wrong but suspect a problem with my Postfix smtp configuration/initial setup.

Please help!

Hrm, that’s odd, as any connection should have completed in well under 60 seconds time :slight_smile:

What do you see in the mail logs – either /var/log/maillog or /var/log/mail.log, depending on your distro.


I’m not too sure how to interpret but from the log file /var/log/maillog:

Sep 2 20:09:36 host1 spamd[3275]: spamd: setuid to heather.planforsuccess succeeded
Sep 2 20:09:36 host1 spamd[3275]: spamd: processing message 2643AA89ACA0F94EB5E8ED83F786F053077AC026@ENT-POCEXCMB10.us.ad.gannett.com for heather.planforsuccess:504
Sep 2 20:09:50 host1 spamd[3275]: spamd: clean message (0.0/5.0) for heather.planforsuccess:504 in 14.2 seconds, 2146 bytes.
Sep 2 20:09:50 host1 spamd[3275]: spamd: result: . 0 - HTML_MESSAGE,MIME_HTML_MOSTLY scantime=14.2,size=2146,user=heather.planforsuccess,uid=504,required_score=5.0,rhost=host1.plexuslogics.local,raddr=,rport=49435,mid=2643AA89ACA0F94EB5E8ED83F786F053077AC026@ENT-POCEXCMB10.us.ad.gannett.com,autolearn=ham
Sep 2 20:09:50 host1 spamd[2968]: prefork: child states: II
Sep 2 20:09:54 host1 postfix/local[21586]: 7ED8137F1E: to=heather.planforsuccess@host1.plexuslogics.local, orig_to=heather@planforsuccess.us, relay=local, delay=31, delays=0.26/0.06/0/31, dsn=2.0.0, status=sent (delivered to command: /usr/bin/procmail-wrapper -o -a $DOMAIN -d $LOGNAME)
Sep 2 20:09:54 host1 postfix/qmgr[3035]: 7ED8137F1E: removed
Sep 2 20:12:43 host1 postfix/anvil[21583]: statistics: max connection rate 1/60s for (smtp: at Sep 2 20:09:23
Sep 2 20:12:43 host1 postfix/anvil[21583]: statistics: max connection count 1 for (smtp: at Sep 2 20:09:23
Sep 2 20:12:43 host1 postfix/anvil[21583]: statistics: max cache size 1 at Sep 2 20:09:23
Sep 2 20:22:01 host1 dovecot: pop3-login: Login: user=<heather.planforsuccess>, method=PLAIN, rip=::ffff:, lip=::ffff:
Sep 2 20:22:01 host1 dovecot: POP3(heather.planforsuccess): Disconnected: Logged out top=0/0, retr=0/0, del=0/10, size=38512

Hmm, I don’t see anything in the above that would suggest SMTP wasn’t working.

Are you sure that, between your PC and the server, that you’re able to access SMTP?

That is, can you double-check that the port forwarding there is working – and also that your ISP isn’t blocking SMTP (many do!)?


Actually, I am not sure. Can you suggest a method to test SMTP connectivity. I used to know how to do this with telnet but am on Vista workstation at the moment.

I am not as familiar with SMTP blocking but have heard about this. I am the owner/operator of the equipment and hosting rack between me and the server. Basically, my PC ->comcast broadband ->my firewall (my access rules) -> server. I can make any changes necessary myself and I am pretty certain data-center is not blocking anything.


Hi Carl,

Sorry about the delay – were you ever able to get that working?

I typically test SMTP connectivity using telnet.

On your desktop, you can run something like:


Which will attempt to connect to port 25 on your server.

It’s not uncommon for Comcast to block SMTP, unfortunately. An example describing that is here: