Unexplained Email::Receiver::InvalidPost errors

[lavamind]

@supermathie

The piece that you might be missing is this one:

@Discourse

Set “Custom incoming email address” to the mailing list’s email address (e.g., mailing-list@foo.test)

(remember that Discourse only uses the message headers (To/CC) and does not know the envelope-to address)

For the tor-relays category, I have Custom incoming email address set to tor-relays@lists.torproject.org which I believe matches the To: header of the mails sent out by Mailman.