documentation

[mbp]

In order for this to really help it would be up to the "senders" to
send to the correct address.  One problem we already have is a
dizzying number of different mail aliases which all expand to the same
group of people, with the result that senders frequently send mail to
the wrong alias.  In the end we end up having to look through several
different logs to find all mail on a particular subject.

--Mark