We have an account for an info@ email. Usually we get some spam, but we saw in the last days that 1 email is shown thousands of times.
But in fact the email arrives only once... I can see that because we have a Daemon that collects all mail via POP3 and sends them to Exchange.
This email is only once in our logs. What is Exchange doing here.
I can delete them but they show up again a view minutes later.
The message Id and the header files of the message show me that this is only 1 mail shown now >10000 times.
We are using Exchange 2016. And the latest CU and security packs are installed.
EDIT: I compared the complete header section of 4 emails. They are completely equal.
EDIT2: The emails are visible over OWA and the Outlook Client.
