I have just noticed that I stopped receiving mail from a discourse (email@example.com) about 14 days ago. My email address is still correct.
In my PM on the discourse instance (that obviously I don’t go checking often because discourse is supposed to send me email), discourse told me that “we’re having trouble reaching you via email”.
My mail server has been half-down about 14 days ago, when my SMTP server was accepting messages but my antispam was down and thus mail stayed in the queue. My SMTP server thus sent mail delay warnings.
However, it looks like discourse interpreted these delay warnings as “Our last few emails to you have all bounced back as undeliverable.”.
This is wrong, and the mail that got sent to Discourse is like the following:
Subject: Delivery status notification: delayed Hi! This is the MAILER-DAEMON, please DO NOT REPLY to this email. A message is delayed for more than 4 hours for the following list of recipients: [...]: Network error on destination MXs Please note that this is only a temporary failure report. The message is kept in the queue for up to 7 days. You DO NOT NEED to re-send the message to these recipients. Below is a copy of the original message: [...]
Note the caps “You DO NOT NEED to re-send the message to these recipients.”, and the
Subject line that clearly states “delayed”. Nothing has gone wrong in the mail setup, and intermittent downtime is supposed to be expected from SMTP servers. This is not a non-delivery notification.
In addition, the discourse UI shows no indication that the mail sending has been stopped. I have just tried to change my email address, and hope this will turn ML mode on again… let’s see what happens.