[exim] Using TLS to encrypt SMTP traffic...

I'm not sure that I even have the subject of this message accurate. I am
trying to make sure that I understand this encryption scheme correctly.
Please can someone correct me if I am wrong on the next statement:

If I configure my Exim4 server to use TLS then the order of the way things
should work after that is:

1. I request an SMTP connection to my server
2. It responds and initiates a TLS connection with the client.
3. I then authenticate using something like SASL and don't need to worry
about the username or password being "sniffed" or intercepted in any other
way.

Thanks,

Jon