Linode Forum
https://forum.linode.com/

SMTP works only inside the box
https://forum.linode.com/viewtopic.php?f=11&t=5241		 Page 1 of 1
Author:  sea0920 [ Thu Feb 25, 2010 1:36 am ]
Post subject:  SMTP works only inside the box
Hello, everyone!

I just set up a sendmail in my CentOS 5.3 linux box.

And I am having problem accessing SMTP from the outside network.

When I try to telnet to SMTP inside linux console, it's okay.

Basically I used the same command in the Linux console and Windows Command Prompt.

Code:
telnet mail.example.com 25


I can ping to the mail.example.com so it's not DNS or ip problem.

I used iptables command to see if I set up firewalls but i didn't.
Code:
iptables -L


Any clues?[/code]
Author:  vonskippy [ Thu Feb 25, 2010 1:52 am ]
Post subject: 
I'd run....

#service iptables stop

just to make sure.
Author:  hoopycat [ Thu Feb 25, 2010 9:39 am ]
Post subject: 
Can you connect to other port 25s? Many (most?) ISPs block outgoing traffic to port 25 to cut down on outgoing spam from hijacked computers.

Try:

Code:
telnet mail.hoopycat.com 25


I *know* that one's up and reachable. :-)
Author:  sea0920 [ Fri Feb 26, 2010 1:47 am ]
Post subject: 
hoopycat

You are right!!

I tried your code and it didn't work. I guess I need to use ISP's SMTP.
Author:  Xan [ Fri Feb 26, 2010 4:39 am ]
Post subject: 
There are some other options. You could use an SSH tunnel. Or you could use the submission port (587 I believe).
Author:  dbb [ Fri Feb 26, 2010 8:19 am ]
Post subject: 
Xan wrote:
There are some other options. You could use an SSH tunnel. Or you could use the submission port (587 I believe).

Yeah, I've used 587 ever since Verizon started blocking 25.
Page 1 of 1 All times are UTC-04:00
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/