Yes. The unencrypted SMTP protocol is considered insecure and is often used to generate SPAM. Originally, the Simple Mail Transfer Protocol (SMTP) used port 25. Today, SMTP should instead use port 587 - this is the port for encrypted email transmissions using SMTP Secure (SMTPS).
Port 465 is also used sometimes for SMTPS. However, this is an outdated implementation and port 587 should be used if possible.
Both port 465 and port 587 are open.
