mention authenticated SMTP from ports in Sec 28.9

[Anton Shterenlikht]

I've been using smtp auth, as per handbook
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/SMTP-Auth.html
for years.

Lately I'm trying to move to binary updates on amd64,
which means not rebuilding parts of the world by hand.

So I installed mail/sendmail package which is
built with authentication support (sendmail+tls+sasl2-8.15.1).
I followed the config instructions at the end of the install
message and things seem to work fine.

I think it's worth mentioning, at the very beginning of
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/SMTP-Auth.html
that using sendmail from ports is a convenient alternative to
these instructions.

Are there any downsides to using sendmail from ports
vs the OS sendmail?

Anton