There are many reasons why emails sent from discourse bounce, the most frequent one is probably a bad sending IP at your mail provider. Nothing can be done about this in discourse.
On the other end of the spectrum are closed email accounts (not so infrequent in academia when people move to a new usiversity for example). Much can be done by the user to fix this, obviously.
Somewhere in between these two extremes are cases where the emails get rejected based on the policy of the recipient server, which means that - depending on who controls the relevant policy, the user can potentially change that policy to make sure your emails get through (I seem to remember that on exchange servers this can be as easy as including the sending address in your address book, but I can’t find the evidence right now).
The easiest way to deal with all of those bouncing emails is probably to simply ignore them and let users figure out why they are not getting any mails from the forum. But here I’d like to discuss what kind of assistance discourse might be able to offer if you do not want to ignore those bounces where users can help improve the situation.
The basic challenge (at least on non-tech forums) is to inform the users about the problem. Currently, I’m doing this manually by sending them an email from a separate email account (using their new email address if I can find it via google). But it would be nice if discourse could help me with contacting users whose emails are bouncing.
In a way it already does so by giving me the user’s email address as a mailto-link in the Emails -> Bounces tab. But it would be nice to stay inside discourse when doing this.
So, for example, there could be a button next to each row in the bounced email list saying “contact user” or something like that. Clicking that button would bring up the discourse editor for a PM (which would allow me to use canned replies) with the only difference being that
- I can specify an alternative email address for the user which is used instead of the one saved in the user’s profile
- The email will not be sent through the usual email provider (mailgun etc) but through an ordinary email account (whose smtp server would have to be added to the site settings).