Port 995 — POP3S
TCP well-known
What runs on port 995
POP3 over TLS.
Security considerations
Use this rather than 110, though IMAP is a better protocol for most people.
Checking whether something is listening
# Linux / macOS — what is bound to the port
sudo lsof -i :995
sudo ss -lntp | grep :995
# Windows
netstat -ano | findstr :995
Get-NetTCPConnection -LocalPort 995
# is it reachable from outside?
nc -zv example.com 995
curl -v telnet://example.com:995
Freeing the port
# find the process, then stop it
sudo lsof -ti :995 | xargs kill # Linux / macOS
netstat -ano | findstr :995 # note the PID, then:
taskkill /PID <pid> /F # Windows