My System is trying to connect with email server on port 25. Recently email server enable TLS on port 25. My application is not able to connect with email server. As per Pega help TLSSTAR will work on port 587. I checked with email server team and they don't have port 587 opened for TLS...Is there any config where i can use TLSSTAR on port 25?
It's worth noting that STARTTLS and TLS are not the same thing and the rule form configuration will differ for each. So you will want to verify with your server team if the channel is secured by STARTTLS or if SSL/TLS is required.
Additionally, it's worth noting that some exchange servers might not allow communication on unsecured channels, so you may need the correct certificates installed in the application server regardless of which situation applies to you.
It is not required for you to use port 587 with STARTTLS, it's just a recommendation.
After re-reviewing your screen shots, I see the User ID field is not populated. In Pega 7.x there is an issue where leaving that blank will cause the test connection to fail. Please try populating that field and testing again. If it is still failing, we may need to see the underlying error from the logs and potentially enable some debug.
The following article has some good setup and troubleshooting information: