TLS vs SSL

TLS vs SSL

Hi there !

There is something I don't really understand regarding SMTP encryption.

The documentation says that port 465 is for SSL, and port 587 for TLS.

I have two questions :
  1. I am not an expert, but for what I know, everybody agrees that SSL should not be used anymore, only TLS is secure. Why offer the SSL option, then ?
  2. When I do some tests using openssl, it seems to me that :
    1. No encryption is available on port 587.
      And I get the error "SSL routines:ssl3_get_record:wrong version number"
    2. Port 465 is using TLS v1.2
            I attached the logs of those tests.

So, is there something that I really do not understand ?
Is the documentation obsolete ?
And more importantly : which SMTP settings should I use if I want to be sure that my email transactions whith Zoho's servers are safe ?

Thanks !