mention authenticated SMTP from ports in Sec 28.9

[Benjamin Kaduk]

On Thu, 30 Jul 2015, Anton Shterenlikht wrote:

> 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.

That's probably a good idea.  It seems likely that there was not a
sendmail port that defaulted to having authentication support at the time
this section was written, not to mention being present in a usable package
system.

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

I think the only issues are generic ones to having a software installed in
both the base system and from ports, involving making sure everything is
using the version from ports, and what happens during early startup before
/usr/local is ready.  I don't expect it to be particularly onerous for the
case of sendmail.

-Ben