SMTP timeout from server a to server b. telnet <serverb> 26 works, but not port 25

ttremain

Well-Known Member
Feb 16, 2003
251
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168
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Root Administrator
SMTP timeout from server a to server b.

telnet <server b> 26 works, but port 25 times out.
traceroute <server b> -p 25 works just fine.

APF firewall and cphulk both disabled on both servers to run tests.

I'm unsure what else to look at

Please advise
 

GOT

Get Proactive!
PartnerNOC
Apr 8, 2003
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Well first step is to determine which server the issue is on. So try telneting to server b from a different server. This will tell you is the hang up is on server a or server b.
 

ttremain

Well-Known Member
Feb 16, 2003
251
3
168
cPanel Access Level
Root Administrator
Well first step is to determine which server the issue is on. So try telneting to server b from a different server. This will tell you is the hang up is on server a or server b.
Not sure why I didn't think of that test. So a third server can telnet to server b, port 25, just fine.

Anyway, figured it out, and the datacenter blocked outbound port 25 on new devices via hardware
 

cPanelLauren

Product Owner
Staff member
Nov 14, 2017
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This happens pretty frequently. If you have access to the server where it's blocked you can have Exim listen on port 26 at WHM>>Service Configuration>>Service Manager