Port 25 is blocked inbound and outbound

OgreMHDW

Member
Feb 2, 2015
8
0
1
Henderson, Nevada, United Stat
cPanel Access Level
Root Administrator
I am trying to find out what I could have done to "block" port 25.

When attempting to telnet from outside the system, I get:
Microsoft Telnet> open server 25
Connecting To server...Could not open connection to the host, on port 25: Connect failed

I am able to telnet on the server, to itself:
[email protected] [/etc]# telnet server 25
Trying x.x.x.x...
Connected to server.
Escape character is '^]'.
220-server ESMTP Exim 4.89 #1 Tue, 04 Jul 2017 07:57:24 -0700
220-We do not authorize the use of this system to transport unsolicited,
220 and/or bulk e-mail.
I can then perform normal mail commands.

When attempting to telnet from inside to Google:
[email protected] [/etc]# telnet google.com 25
Trying 216.58.219.14...
telnet: connect to address 216.58.219.14: Connection refused
Trying 2607:f8b0:4007:806::200e...
telnet: connect to address 2607:f8b0:4007:806::200e: Network is unreachable

Does anyone have any ideas? I am at a loss of where to go from here.
 

cPanelMichael

Technical Support Community Manager
Staff member
Apr 11, 2011
47,911
2,233
363
cPanel Access Level
DataCenter Provider
Twitter
Hello,

It's not uncommon for service providers to block access to port 25 as a SPAM prevention technique. I recommend contacting them to see if that's the case.

Thank you.