Incoming emails - delay error
I've been asked to look into an issue receiving emails from a certain domain (another school). We can send to them fine, but any messages sent to us get bounced back with:
Firstly - is this a problem at the sender's end, or ours? We are receiving external emails from other domains, and they can send fine to other domains except ours. A quick search seems to say it's a reverse DNS problem, though I can't see why this would be affecting only one sending domain. We have recently installed a second broadband line in parallel to the existing one (which still handles email traffic) - could this be causing the issue?
Delivery is delayed to these recipients or groups: firstname.lastname@example.org
This message hasn't been delivered yet. Delivery will continue to be attempted.
The server will keep trying to deliver this message for the next 1 days, 19 hours and 55 minutes. You'll be notified if the message can't be delivered by that time.