Setting up STMPS over port 465 RRS feed

  • Question

  • I'm trying to implement SMTPS over port 465 but I can't get it to work for the life of me. Is there anything I need to do with the firewall or SMTP server properties to make this happen or am I stuck enabling TLS over port 25?
    Monday, October 14, 2019 8:59 AM

All replies

  • The IIS6-based SMTP service that is included in Windows Server doesn't support SMTPS. It will only encrypt messages using the STARTTLS verb in SMTP sessions. You can set this up to work on port 465, but the encryption process will not start immediately after the session is established. It will still use STARTTLS to encrypt. If you need to have SMTPS running for some reason, you will need to use a different SMTP server solution than what is included in Windows.
    Monday, October 21, 2019 4:30 PM