Better handling of email rejection

[jrivettcsa (Jeff Rivett)]

@justin

If a user is responding from a different address than the one to which the email was sent, this is expected.

Yes, as I said, it makes sense to reject these. But I would still like to be alerted when this happens.

@justin

If contact email forms are in use, they usually send from an email and set the Reply-To header, which means we’re hitting the same problem as stated above.

I only mentioned contact forms because when customers are unable to reach us via the support email address (which Discourse processes), they are forced to look for alternatives, which is not ideal.