+
+ $mime = PublicInbox::Eml->new(<<'EOM');
+Message-ID: <new@host>
+Subject: [ruby-core:13] times
+
+EOM
+ $ret = $f->delivery($mime);
+ is($ret, $mime, "delivery successful");
+ is($mm->num_for('new@host'), 13, 'MM entry created based on Subject');