Port 25 instead of 587

Hello,

WP Mail SMTP only works for me if I set the port to 25 instead of 587 for TLS as my webhoster (1&1 Germany) says. Everything else will result in a timeout. After some research I got the impression that port 25 is somehow outdated or not really recommended anymore. Will the plugin stills send emails encrypted via SSL/TLS with my current setup with port 25?

Regards Timo