Port 465TCP
SMTP on implied TLS, often used for authenticated sending.
What is Port 465 for?
Email. The protocol or service generally associated is SMTPS.
Transport Protocol
TCP
Safety precautions
Check the parameters imposed by the courier provider.
Should we open this port in the firewall?
Only if a service is actually needed the use it. Apply the principle of any privilege: limit the authorized sources, destinations and interfaces, and then log connections when relevant.
How do I check this port?
Test-NetConnection SERVER -Port 465Under Linux, you can use nc -vz SERVER 465.
Port/service associations are common conventions. An application can be configured on another port.