If mailwrapper is to be of any use, all MTAs that install /usr/sbin/sendmail should install /usr/sbin/sendmail.packagename instead. I've written an example ebuild (http://dev.gentoo.org/~ticho/esmtp-0.5.0.ebuild) with message in pkg_postinst() which can be replicated to every MTA that needs to support mailwrapper. Currently, postfix and esmtp (which I am about to add in portage) come into my mind. Does anyone know of other? I'm sure there are more, including sendmail itself.
Oh yes, and these MTAs need to RDEPEND on mailwrapper. I suggest >=mailwrapper-0.2, since location of mailer.conf has changed since 0.1, which IMHO should be removed from portage, as 0.2 is marked stable on all archs.
from postfix stable ebuild. <snip> if use mailwrapper then mv "${D}/usr/sbin/sendmail" "${D}/usr/sbin/sendmail.postfix" </snip> so postfix should be ok.
My apologies, I overlooked that. But, how will a new user know about this feature? I for one didn't know anything about mailwrapper up until now. Shouldn't a warning be issued in case mailwrapper flag is not set AND there is already a MTA installed? MTAs blocking each other (!virtual/mta in DEPEND) is not a good idea for small MTAs, since for example esmtp can nicely be used along with Postfix (my case).
Nevermind, I found the !mailwrapper? ( virtual/mta ) in postfix. I shouldn't be staring at all those tiny letters so early in the morning. Closing this, sorry for bothering. :)