AWS SUSE server can't do telnet on 25 port.

Hello Everyone,

We have AWS SUSE server where we are facing an issue on doing telnet to 25 port to our mail domain.
We have checked the suse is using the sendmail service and we have tried all the possible way but 25 port is open but still we can't do telnet on 25 only, We able to do telnet on all other different port.

We have checked the firewall is not running and update the suse 12 SP4 also but still facing error.

Please help how to solve this issue.

Edited by: saeeda on Nov 7, 2019 11:18 PM