I am using 2 servers (A and B) centos 7. I am trying to telnet from A to mail.smtp2go.com
serverA$ telnet mail.smtp2go.com 2525
Trying 45.33.53.153...
telnet: connect to address 45.33.53.153: Connection refused
Trying 66.228.43.14...
telnet: connect to address 66.228.43.14: Connection refused
Trying 45.79.71.155...
telnet: connect to address 45.79.71.155: Connection refused
Trying 173.255.233.87...
telnet: connect to address 173.255.233.87: Connection refused
which fails and hence i cannot use port 2525 for mail transport. Server A can telnet through 25 port
serverA$ telnet mail.smtp2go.com 25
Trying 45.33.53.153...
Connected to mail.smtp2go.com.
So i am currently using it.
But it makes me crazy when Server B (on same subnet as of Server A) can telnet on port 2525 and 25 both successfully. What could be matter with A ?