I run a virtual email server using Postfix that forwards emails addressed at
domain.com to specific Gmail / Hotmail accounts. This same server also acts as a mail relay, and uses
saslauthd to allow parties to log in and send emails under
Currently, this mail relay only works with port 25 over TLS (you can access it by creating, for e.g., a send-only email address in Gmail). Should I open port 587 for this purpose instead of using port 25? If so, need I disable mail relay access over port 25 (since I read that 587 is used over 25 to reduce spam)?
How do I go about doing this? Is it as simple as adding the
submission port to
master.cf in Postfix?