I'm having an issue right now with a specific distribution list on our Exchange 2007 server. Sending e-mails to it causes exchange to bounce back after several hours with "Delivery is delayed to these recipients or distribution lists: ". No recipients receive the message and it's an internal distribution list. Does anybody know why this could be happening?
It's the second time it's happened, the first time was a couple of months ago.. That time we opened a support case with Microsoft as we were so confused by it.... but never really figured out the exact root cause or why it started working again.
One weird thing I noticed is that despite the fact that Exchange will notify the sender after four hours that the message is delayed... the message does not appear in the Queue viewer