When I installed mail/postfix (under BSD/OS), I see:

===> Registering installation for postfix-2.0.16
pkg_create: Overwriting /usr/pkg/bin/mailq - pkg sendmail-8.12.10
bogus/conflicting?
pkg_create: Overwriting /usr/pkg/bin/newaliases - pkg sendmail-8.12.10
bogus/conflicting?

An easy (but wrong) fix would be to have a

CONFLICTS=	sendmail-[0-9]*

CONFLICTS=	postfix-[0-9]*

(Also, sendmail811 should conflict too. And maybe sendmail811 should
conflict with other sendmail too?)

But then admins can't have both installed at same time -- which is usually
required (i.e. forcing old MTA to run its queue) for migrating from one
mail server to another.

I'd prefer they didn't conflict.

One idea would be to place postfix's mailq and newaliases under
libexec/postfix (and same for sendmail).

This would be especially good for us that use LOCALBASE=/usr and use
mailwrapper (so our mailq and newaliases are not overwritten).

Any ideas?

   Jeremy C. Reed
   http://bsd.reedmedia.net/

p.s. postfix and sendmail do not have MAINTAINERs for pkgsrc.