Topic: How to open up port 26 for SMTP Server

[matt001]

Hi

I have got a domain name and wanting to use it as my smtp servers instead of my ISP SMTP Server, but my ISP Telstra BigPond have closed port 25 and my Web Hosting Provider has enabled Port 26 how do I open port 26 on Contribs SME Server 6.0.1

[trenskow]

Hi... i have the same problem with an danish ISP.. so i would also like to hear from someone who nows  

[raem]

Do you have a Fixed IP or Static IP for your Internet service ?

[trenskow]

Me..??... i have a fixed IP

[trenskow]

isn't there anyone who knows this?  

[sonoracomm]

Sorry for the late entry.  Perhaps it will help someone else...

This is actually a bit of a complicated issue, and fairly common.

You need to get someone to relay your SMTP traffic for you.  In other words, someone needs to accept mail for your domain, then send all that traffic to your server via a port other than 25, which is often blocked by residential ISPs.  This is the hard part.

Getting SME to respond on another port is easy.  

Instructions on modifying SME to accept mail on another port are in this howto I wrote for ASSP:

http://www.sonoracomm.com/sonoracomm/pdf/ASSP_Howto.pdf

G

[jreijsenbach]

Hi G,

I've tried your sugestion and did the following

mkdir -p /etc/e-smith/templates-custom/etc/services/

cp /etc/e-smith/templates/etc/services/10standard /etc/e-smith/templates-custom/etc/services/10standard

pico /etc/e-smith/templates-custom/etc/services/10standard

Changed tcp 25 into 26

/sbin/e-smith/expand-template /etc/services

cat /etc/services|grep smtp

/sbin/e-smith/config setprop smtpfront-qmail TCPPort 26

/sbin/e-smith/signal-event email-update

telnet localhost| 26

The result is:

# telnet localhost 26
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused

I don't know what I did wrong here maybe you can enlighten me? Anyone else who knows please do tell.

Thanks in advance,

Jan

[sonoracomm]

I dunno.

Try rebooting.

Try port 125.

What were the results of "cat /etc/services|grep smtp"?

I've done this MANY times, though only once on a 6.5b1 server.

G

[jreijsenbach]

The results:

smtp            26/tcp          mail
ssmtp           465/tcp                         # SMTP over SSL

But I think maybe the firewall should also be changed? I can portforward but just opening it may be a bit more tricky.

If you can give me a hint I'd appreceate it very much

Thanks,

Jan

[jreijsenbach]

New Problem.... sending mail doesn't work. I tried using webmail but get an error stating it cannot connect to smtp on localhost port 25. With Outlook I get a time out.

What am I missing here?

anybody?

Jan

[sonoracomm]

Well, you wanted to change the SMTP port...

So, you don't really want to change the SMTP port.  You want the SMTP daemon to listen on another port AS WELL.

Options:

1)  You may look into the new 6.5.  I think it has some upgrades in this area.  You may look into using SSMTP.  That port may not be blocked by your ISP.  You'd need the same forwarding arrangement, probably, but it probably isn't blocked.

2)  Go ahead and install the ASSP spam filter.  It will do what you want AND give you spam filtering.  You may have to forward the new port (26?) from your firewall to the server...or whatever.

G

[CharlieBrady]

Well, you wanted to change the SMTP port...

So, you don't really want to change the SMTP port.  You want the SMTP daemon to listen on another port AS WELL.

Options:
...

You left off a third option - portforward port 26 to localhost port 25.

[jreijsenbach]

Hello Charlie,

question about your solution:
This portforwarding only works for incoming e-mail traffic?

If so it seems a cleaner solution. In order for me to try it I will need to undo the custom template I presume. Please correct me if I'm wrong, the procedure would be as follows:

remove /etc/e-smith/templates-custom/etc/services/10standard

do /sbin/e-smith/expand-template /etc/services

do /sbin/e-smith/config setprop smtpfront-qmail TCPPort 25

do reboot

And all should work as before?

Now do portforwarding of all incoming tcp 26 on 127.0.0.1 to tcp 25

And that should do it.... I'm guessing here so before I completely destroy this installation I thought I'd better ask the experts

Thanks a lot for all the help!

Jan

[CharlieBrady]

This portforwarding only works for incoming e-mail traffic?

Yes

If so it seems a cleaner solution. In order for me to try it I will need to undo the custom template I presume. Please correct me if I'm wrong, the procedure would be as follows:

remove /etc/e-smith/templates-custom/etc/services/10standard

do /sbin/e-smith/expand-template /etc/services

do /sbin/e-smith/config setprop smtpfront-qmail TCPPort 25

do reboot

Just do:

/sbin/e-smith/signal-event email-update

instead of the reboot.

And that should do it....

That should do it. If it doesn't, it's a bug in port forwarding, so report it in the bug tracker on this website.

[jreijsenbach]

Hi Charlie,

Well mus be a bug then, will make a bug report right after this response.

Ok problem is when I just portforward nothing happens as far as I can see.

When I use the first option mentioned in the early part of this thread I can receive mail. There are some nasty side effects though:
1. I cannot send any mail because sme seems to block port 25 outgoing.
If I want to use another mailserver on the internet for sending mail (for instance my ISP's smtp) outgoing traffic is blocked on port 25.

2. Webmail keeps trying to connect on port 25 instead of 26 when sending mail.

I have too little knowledge to find out how to make sure my port 25 is closed. And also no knowledge how to open it. I tried:
1. portforwarding => no result
2. portopening => no result

I think this should be fixed manually but I am at a loss how?

If any of you out there can assist in supplying instructions please do so.

Thanks for all your advise so far,

Jan

PS I am not sure if it is possible, but can it be done to make the incoming port 26 and the outgoing port 25 for one and the same mailserver?