I have not read of any issues with the mail server other than the ongoing issues with Yahoo mail and the slow webmail portal from time to time. If the mail server is on a go slow it normally rectifies itself after a short period.
This is happening to me too and it is driving me mad! Tried an Optus help chat window and the tech basically said it was fault of everything else except Optus.
Emails from multiple sources are being delayed 1-2 hours (sometimes longer). But only SOME emails, not ALL. For example, a client will send me two emails at same time and one will come though immediately and the other one will arrive 2 hours later. But still timestamped the same as the first email. I have tried using optus webmail direct, but that doesnt solve the issue. Attachments are not the issue. And I'm well below my inbox quota.
We have had this problem many times over our years with Optusnet. A few years back when we chased up with Optus, they explained there was a problem with one of their incoming mail servers (hence the delay only happening to some emails) and they would fix it. They did. Then when the problem occured after that we were just patient and it righted itself within a day or so. But over the last year the problem has become more frequent. And over the last 2 weeks it is every day!
You only have to search 'delayed emails' on this forum to see how often this problem occurs! Why do the online chat techies not know about this problem, given how frequently people complain about it? And why is it not being fixed?