Technical Information: Linux Sever, Qmail, Oempro Bulk Email Marketing Software installed on the server
Problem: Identified yesterday. Emails being sent via Oempro are not being received.
When logged into the Oempro software the campaigns show as sent. I have run some test email campaigns to send to my own email addresses and no emails have come through.
This was working without problem last week. No changes have been made to Oempro. No known changes made on the server.
The IP address of the server has been on a couple of blacklists but this has been the case for a long time and has never caused issues like this in the past.
There is a large backlog in the mail queue which does not seem to be going down.
messages in queue: 539867
messages in queue but not yet preprocessed: 298806
I need someone who is able to investigate this problem immediately, be able to explain the problem to me and fix the problem so emails start sending as expected again.