If an email gets stuck in postfix’s deferred queue, there are a couple of ways to deal with it.
Category: email
Email servers (postfix, dovecot) in Linux
Mailing List
For general discussion, the “discuss” list:
https://lists.bclug.ca/mailman/listinfo/discuss
Alternately, send an email to discuss-subscribe@lists.bclug.ca, then simply reply to the confirmation email message.