[CentOS] sendmail sending out on port 587

Gregory P. Ennis PoMec at PoMec.Net
Mon Mar 22 04:55:52 UTC 2010

On Sun, 2010-03-21 at 15:55 -0500, Gregory P. Ennis wrote:
> Dear List,
> I recently spent some time out of the USA, and found myself in a hotel
> that blocked port 25 which prevented my laptop's ability to connect to
> my office mail server.  I did a scan on the internet and made the
> observation that this was a common problem.  I had port 22 available so
> I was able to get my office server set up to accept mail on 25 and 587
> without difficulty.  The command "telnet mail.server.com 587" to my
> office mail server connects without difficulty.  
> However, I have not been able to get sendmail on my laptop to connect to
> sendmail on my mail server at home using port 587.  
> I have added the following to sendmail.mc on my laptop without success :
> define(`RELAY_MAILER_ARGS', `TCP $h 587')
> define(`ESMTP_MAILER_ARGS', `TCP $h 587')
> I finally made it back home, but have decided to change my configuration
> to use 587 by default so that this problem will be avoided, but I have
> been unable to get my laptop to connect.   
> Anyone having ideas would be appreciated.
> Greg Ennis


Thank you for your assistance; the best solution seemed to be the use of
openvpn, or changing to thunderbird instead of evolution.  I never found
a method to make sendmail send mail out on 587.

However, I did find an easy solution for evolution to use smtp on port
587.  I will record it here so that anyone looking for this in the
future will have the right methodology. 

All I had to do was to place the port number after the server name in
the "Sending E-Mail" tab of the "Preference -> Mail Account module in
the form of :


It was easy to set sendmail up to use port 587 with the entries :

DAEMON_OPTIONS(`Port=smtp, Name=MTA')dnl
DAEMON_OPTIONS(`Port=submission, Name=MSA, M=Ea')dnl

Please note both entries are required for sendmail to use port 25 and
port 587.

Thanks again for everyone's help!!!


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