Second SMTP Port on DA-Server

[ATN Networks]

Hi There,

Some internet services providers who offer DSL connections to their customers are bussy to block all 3th-party SMTP servers. To do this they simply block outgoing port 25 (SMTP) by all DSL customers.

Some of our customers are using a DSL connection from some of this providers. We standard offer a SMTP option to all of our customers cause they trust our servers more then the servers of this providers.

Is there any way to made a config on our DirectAdmin based server that this customers can connect the SMTP via an other port like 26 (or something) and port 25 on the same server??

Hope that someone can help me.

 

[nobaloney]

DA's exim mailserver by default also accepts email from authenticated users, for relaying, on port 587, which according to the RFCs is the autenticated submission port, and therefore the right port to use .

Jeff

 

[ATN Networks]

Nice, but mutch customers are just simple appeared. Its easier for them to use the SMTP on a other port.

Because there are a lot of user who can use the SMTP port without this problem I don't want to tell them all that they have to use an other port. That's why I want to have a second SMTP port on that server.

 

[floyd]

Wait a minute. You said:

Its easier for them to use the SMTP on a other port.

And then you said:

I don't want to tell them all that they have to use an other port.

How are they going to use another port if you don't tell them what it is?

Exim is already configured for two ports so I guess what you are saying is that you need it to listen on a third port. So just open exim.conf and add the third port.

 

[ATN Networks]

Ok, thanks for your reply. It's working great
Now we can make a lot people very hapy ;-).

 

[kke]

Nice, but mutch customers are just simple appeared. Its easier for them to use the SMTP on a other port.

Because there are a lot of user who can use the SMTP port without this problem I don't want to tell them all that they have to use an other port. That's why I want to have a second SMTP port on that server.

I think you misunderstood, that you have to tell all your customer to use port 587.

Both 25 and 587 are accept then just leave all customer use standard 25 port, and just tell people who have problem to use 587

If you have firewall, check that port 587 is allow.

 

[Maniak]

Hi,

As seen on WHG, you can do this (should work on Fedora/RedHat/CentOS) :

$IPTABLES -t nat -A PREROUTING -t nat -p tcp -d SERVER_IP_HERE --dport 26 -j DNAT --to SERVER_IP_HERE:25

and then restart it

service iptables restart

Then just tell your customer to use port 26.

 

[nobaloney]

Why not use the official port set up for the service, port 587. While no ISPs should ever block port 587, they may (or network administrators may) block ports on which they see unauthorized traffic.

Actually, port 26 is used by RSFTP (A simple FTP-like protocol), see this Wikipedia article.

Jeff