PostfixAdmin and System Messages

[Carmel NY]

On Wed, 21 Jun 2017 11:21:18 -0500, Greg Groth stated:

> After 20 years of Sendmail, I've built a new mail server using the 
> guidelines outlined at purplehat.org.  So far, everything is working 
> great except that my system messages that used to be delivered to my 
> account are MIA.  I do have an alias in /etc/aliases from root to my 
> email address hosted on the same server, but I don't know if
> Postfix / PostfixAdmin uses the /etc/aliases when configured to use
> virtual aliases.  I also added a virtual alias from
> root at domainname.com to user at domainname.com
> 
> A little more history: In the purplehat.org documentation was the 
> following note.
> 
> <quote>
> 
> If you are receiving errors in your logs about $mydestination, be
> sure that _ANY_ ‘virtual’ domain you are hosting is _NOT_ listed in
> your /etc/hosts file. Apparently this causes a problem being as
> Postfix cannot determine if the domain is virtual or not. (Thanks
> Valentin)
> 
> </quote>
> 
> I am only running a single doman on the server, but because of the
> above message, I specifically avoided entering the mail server's
> internal IP address and FQDN in /etc/hosts.  However, when I looked
> at my maillog I noted that Postfix was trying to send the system
> emails to my mail server's outside IP address, which obviously didn't
> reply.
> 
> While I run my own DNS server on the same box as my mail server, it's 
> serving the external IP addresses to the outside world.  It's
> currently 1 of 2 machines on my DMZ, which has a non-routable IP
> range of 192.168.100.X.  Because of there only being two machines, I
> use /etc/hosts for any needed name resolution on the network, and my 
> /etc/resolv.conf is pointed at 8.8.8.8 & 8.8.4.4.
> 
> Because of this issue, I then decided to try adding an entry to my 
> /etc/hosts file :
> 
> 192.168.100.10        domainname.com        mail.domainname.com
> 
> Now when I check the maillog, although it is now finding the mail 
> server, I see that my system emails are now being routed to 
> root at mail.domainname.com instead of root at domainname.com.
> 
> Based on what I'm seeing, I'm assuming that this is more of a DNS
> issue than Postfix, I'm just not sure if I can use the hosts file to
> fix it or if I should try to install a local DNS server just for my
> DMZ for the system emails?   Other than the system emails, everything
> else has been working great.  Any thoughts?

Just a thought, but you might be better off asking your "postfix"
questions on the "postfix forum". Do include the info as requested from
this URL: http://www.postfix.org/DEBUG_README.html and in particular
this one: http://www.postfix.org/DEBUG_README.html#mail

Good luck!

-- 
Carmel