postfix can olso use milters like sendmail so i belive this ebuild blocks to much
Steps to Reproduce:
1. emerge -av mail-filter/dkim-milter
error is shown
*** Bug 224133 has been marked as a duplicate of this bug. ***
Without any output given it's hard to say, but on Gentoo the MTAs block each other because of file collisions, unless you install them with the mailwrapper use flag set. But this is going to change afaik. Please provide emerge --info and the exact blocker output Portage spits out.
What I'm a bit wondering about is why libmilter is only blocking sendmail and not virtual/mta (assuming that it does install a sendmail binary/symlink/script just as Postfix or other MTAs do.
Created attachment 154759 [details]
my emerge info
Created attachment 154761 [details]
emerge -pv mail-filter/dkim-milter
dkim-milter depends on sendmail which blocks other mta's (and vice versa) as Carlo explained, therefore you can't install dkim-milter together with postfix.
I'll close this one as CANTFIX, but add our maintainers for dkim-milter for advise - if it's possible to run dkim-milter without sendmail but postfix instead please re-open this bug.
You can install dkim-milter (or any other milter for that matter) with postfix. All you need to do is make sure mail-filter/libmilter is installed, which is in fact the libmilter static library taken from the sendmail package.
To be more exact, the *-milter dependency atom is "|| ( mail-filter/libmilter mail-mta/sendmail )", which should satisfy both cases:
1) sendmail users - MTA program usually gets installed usually before additional software
2) postfix users - libmilter is the preferred dependency
However the 2nd scenario has a weak spot, namely libmilter has only x86 and ~amd64 keywords. I will open a stabilization bug for amd64.