Postfix SMTP Port 25 Problem/Question

[ccix]

I've had a email server setup for awhile now with sendmail. i've since installed a new hard drive and started with the fresh setup for the debian 3.1 how to. Everything seems to work great except this....

If i'm on the local host i can telnet to port 25 and send mail/etc.... But if i try to login from outside the domain (say from dialup or not from my office...at my parents house) it doesn't connect, just times out? What am i missing? Is there a setting i missed. Followed the setup perfectly (set it up a few times actually why playing around). One note, i'm not using ISPCONFIG.

Any help would be appreciated.

Eric

[falko]

Are you using Sendmail or Postfix right now? If you use Postfix, have a look at the

inet_interfaces

setting in /etc/postfix/main.cf, if you use Sendmail, have a look here: http://www.howtoforge.com/forums/showthread.php?t=25

Might also be a firewall problem. Please post the output of

iptables -L

[ccix]

I am using Postfix (setup via the howto for the perfect setup+SQL/auth/etc)

inet_interfaces = all

ns:/etc/postfix# iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination

Chain FORWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination


mail server is mail.ccix.com if you'd like to telnet in and see what happens.... any other ideas? Let me know if you want a copy of any other config settings/files.


Eric

[themachine]

are you behind a firewall??? if so, perhaps you need to open the port up and configure port forwarding... by default the port is probably blocked at the firewall.

[ccix]

No physical firewall in front of the server. If i plugin the old harddrive and use my old setup then i can send email fine through sendmail (was using debian 3.0 ...worked okay but i liked the way the howto setup things this way).

So definately no firewall (Cisco 675 for DSL, then into a 4 port up ...where the server is connected directly).

[themachine]

You might want to contact your ISP and inquire as to whether they block port 25 or not. I see customers all the time that cannot send/receive SMTP email *exect* through the servers that are provided by the ISP. It is likely that port 25 is being blocked at the ISP level.

[ccix]

Not sure what i did but it seems to work now for the most part. I can't connect to it via dial up but if i'm on my cell phone connection it works fine. No ISP blocking anything (Qwest DSL line,do what ya want with it is pretty much what i was told and i had a server running 2 days ago without any problem). Thanks for the suggestions though.

[falko]

Originally Posted by ccix

Not sure what i did but it seems to work now for the most part. I can't connect to it via dial up but if i'm on my cell phone connection it works fine.

Maybe it's the firewall on your client that is blocking?

[AgeOfPenguins-com]

I know for a fact my ISP is blocking port 25.

How do I set up my mail server to use port 26?

Matthew

[themachine]

Honestly, I would rather create a port redirect, rather than change the port which the mail server listens on. Then, you simply change the port within your mail client. I have some IPTABLES examples on how to create Port redirects:

http://www.5dollarwhitebox.org/wiki/...Port_Redirects


Setup:

Add the Iptables rules to create the redirect so that any traffic going to port 26 is redirected to 25. In your mail client, configure SMTP to connect to your server on port 26.

Let me know if you need any help.