Can't send email from outside

Hello

I use ISPconfig v3.0.16 for a long time.
Today I found I can't send email from outside network.
I can't connect the ispconfig server use
telnet mail.mymail.com 25
from outside network
but I can connect it in the local network.
I have set the DMZ to the ispconfig server.
and check the Centos5.3 have no firewall.
anyone can give me hits
thank you very much !!!

 

maybe your ISP (home) disallows to use port 25

Here, one of the big ISPs blocks all port 25 connections from home dsl users. Instead they have to use port 587 -> http://www.swisscom.ch/res/hilfe/sicherheit/spam25/index.htm

maybe your ISP does the same.

 

Thanks Reply

But we use business line, all ports is not block by ISP.
And all incoming and outgoing email have no problem.
Because some staff need send email from home though
the ispconfig email server. So we found that problem.

Do I need post some information for yours help ?
Thank you very much !!!

 

Any errors in your mail log?