bug 5890: pick 0.28 as a reasonable minimum version for Mail::DKIM
bug 5890: pick 0.28 as a reasonable minimum version for Mail::DKIM

git-svn-id: e9fe9b84e32fc5e57b7d09c40cd78b14ea28ed71@651565 13f79535-47bb-0310-9956-ffa450edef68

apache/spamassassin,apache/spamassassin,apache/spamassassin,apache/spamassassin,apache/spamassassin