Browsing through printed material (plain curiosity) in section 6.3 of
"Reference Guide" I run onto this (the last paragraph on page 90):

"Please be aware that if you configure your system to masquerade as
another, any email sent from your system to your system will be sent
to the machine you are masquerading as.  For example, in the above
illustration, log files that are periodically sent to
root.com by the cron daemon would be sent to
root.com."

I could take the above at the face value, adding on the top of it few
nasty comments how broken is sendmail, if not that small detail that
I _know_ that in real life the quoted paragraph is plain false.

Also the whole preceding text is rather doubtful.  I understand that
this possibly not the place to talk about MX records, and other things
like that, but what is written can be interpreted that sticking few
names in sendmail.cw on mail.bigcorp.com will magically make it to
receive mail for 'torgo', 'poodle', 'devel', ...  even if they are
separate boxes with their own addresses in 'bigcorp.com' domain.
Well, that way you create only a big mess.  I do hope that folks
responsible for such setups learn that from some other sources.