What problems can arise when using a self-signed certificate on a mail server?

Question

Email

There was a question of a raising ssl on mdaemon-e. I would like to understand if I can use a self-signed certificate and expose it to the outside? Access to mail occurs either through a vpn network or through a local network. But one of the new services refuses to work without ssl. What problems can there be with the mail server in this case?
Thank you.

Answer 1

Using SSL on SMTP will in some cases fallback to a non-encrypted protocol if the sending party does not accept a self-signed certificate. This is not a special case, i.e. usually relays do not check the certificate. But in any case, it's better than no SSL at all.
+ you will have to install your certificate in the list of trusted on all clients.

Answer 2

none. for personal needs, I don’t care what you sign there. just add the root certificate to the trusted centers and live in peace