Hello, I run a small mailcow server for my company. It has several domains and around 8 mailboxes currently.
I just started receiving this feedback from some of the other users about receiving duplicate emails. I confirmed this by logging into their mailboxes and seeing the emails arriving. Today I got a report saying the system was also sending duplicate emails. Up to and possibly over fifty duplicates of one email was sent to one of their customers.
I’m just not sure where to begin troubleshooting this. At first, I thought it might be just emails they received getting queued by the sender because postfix was reading a received message like normal with the duplicates.
Then I checked the postqueue but that is empty. All the other machines seem to be working without issue. And then I performed an update, but it seems to still be continuing.
Any ideas would be appreciated. Thank you very much!