Changing SMTP MTA port

**jportes** · 09-08-2005, 07:14 PM

Is it possible to change the default smtp port (ie 25) for something else ?

It will be great because lot's of ISP block the 25 IP Port...

Thanks

**KevinH** · 09-08-2005, 09:42 PM

The MTA runs on 7075 and is mapped to port 25 via iptables. So you can try working with 7075 and see if that avoids your ISP's filtering.

-kevin

**bob_p** · 09-09-2005, 08:27 AM

Is there any document you have that will allow me to (heavily) firewall this system from the internet?

Thanks,

Bob

**marcmac** · 09-09-2005, 11:47 AM

Originally Posted by bob_p

Is there any document you have that will allow me to (heavily) firewall this system from the internet?

Thanks,

Bob

The ports that we use are listed here:
Questions Before I Start

So, as long as those are available (just the mapped ports), you won't have any unused ports open.

Also, you'll want to plan you service according to your security concerns - offer only SSL enabled services to the public network, etc.

**bob_p** · 09-09-2005, 06:20 PM

Thanks for the info.

My next question is where can I DISABLE your iptables firewall rules? I would like to incorporate these with our standard Shorewall ruleset to make the installation a lot easier and more more uniform?

We have a RHEL4 (CentOS) kickstart CD we use, and I would love to figire out how to incorporate this into that CD.

Thanks,

Bob

**marcmac** · 09-09-2005, 06:22 PM

Originally Posted by bob_p

Thanks for the info.

My next question is where can I DISABLE your iptables firewall rules? I would like to incorporate these with our standard Shorewall ruleset to make the installation a lot easier and more more uniform?

We have a RHEL4 (CentOS) kickstart CD we use, and I would love to figire out how to incorporate this into that CD.

Thanks,

Bob

The iptables rules are installed with the script /opt/zimbra/bin/zmiptables - the option to remove the rules is -u.

**PhishKiller** · 10-24-2008, 08:53 AM

I was just called by the CEO of our company, needed to know which alternate port I can configure Zimbra to use, since at the last confrence port 25 was blocked by the network used by the conference network infrastructure people. I'm sure many can understand how important this issue is to me, right now!

How much of this is thread relevant to Versions 5.0...? I've not yet found another other good search result, so I'm trying this OLD thrat.

These tricks did not work on our Zimbra 5.x system. It does not look like Zimbra is using 7075 any longer and the iptables file listed does not exist:

Starting Nmap 4.00 ( Nmap - Free Security Scanner For Network Exploration & Security Audits. ) at 2008-10-24 08:46 PDT
Interesting ports on mail.mydomainobscured.com (0.0.0.0):
(The 1663 ports scanned but not shown below are in state: closed)
PORT STATE SERVICE
22/tcp open ssh
25/tcp open smtp
111/tcp open rpcbind
389/tcp open ldap
443/tcp open https
465/tcp open smtps
623/tcp filtered unknown
664/tcp filtered unknown
796/tcp open unknown

Need some help here to us another port besides 25!