On Thu, Sep 13, 2012 at 05:32:29AM +0200, M. Fioretti wrote:
> On Wed, Sep 12, 2012 12:19:58 PM -0500, Noel Jones wrote:
> > > Sep 12 18:54:33 avalon sendmail[11515]: q8CGsUYa011515:
> > 
> > Oops, looks as if you have sendmail still active.  The postfix
> > warranty is void if you're running more than one MTA.  That could
> > well be the whole trouble.
> 
> If we will receive this email of mine through the list, that was
> indeed the whole trouble and the problem is solved. Sure enough,
> sendmail was still active on this laptop, unlike on my previous
> computer. Now I have erased it and restarted postfix.
> 
> I assume that I did not consider or see this really simple answer
> because I did not see any notification that I had two MTAs running
> both when I started postfix manually at the command line and in
> /var/log/maillog. Is this a bug?

No, a misunderstanding. You cannot actually "run" two MTAs without 
specially configuring at least one of them; Sendmail as a daemon is 
going to bind and listen on port 25, as is Postfix. If Sendmail had 
been running as a daemon, "postfix start" would indeed return and log 
an error when it was unable to bind 25. Likewise, starting Sendmail 
(as a daemon: the same binary also handles command line submission) 
would cause an error if Postfix was already running.

What you had was the Sendmail sendmail(1) binary in place of the 
Postfix one. So your MUA which used sendmail for submission got the 
Sendmail sendmail. I think when Sendmail is not running as a daemon, 
its sendmail submission acts like a null client, connecting to 
localhost:25 (or as configured) to relay the mail.

In rare (lucky) cases it might actually work! But usually not.

Distributions and OSs which offer multiple MTAs generally also 
provide a means to choose which one is active and has its sendmail(1) 
binary in place where MUAs will expect to find it. For example, RHEL 
has alternatives(8):

# alternatives --set mta /usr/sbin/sendmail.postfix
-- 
  http://rob0.nodns4.us/ -- system administration and consulting
  Offlist GMX mail is seen only if "/dev/rob0" is in the Subject:

Reply via email to