Bugmail from bug 491110 comment 5 did not reach the firstname.lastname@example.org mail alias. However, the mail from bug 491110 comment 4 (which was posted almost at the same time) arrived.
Mails may be delayed (up to several minutes or even longer) when a destination address is no longer valid or the remote SMTP doesn't accept the mail. This is a bug (by design?) in mlmmj. It stops processing any further mails for some time instead of just skipping "broken" ones. So that mail should have arrived later.