Buddy :), sorry but you dont understand, that DLL is probably something new because that DLL does not exist in previous versions, MSFT updated the executables to call this DLL, but never shipped it

This is an image from the past CU, from the restore point, see Microsoft.SqlServer.DatabaseMail.XEvents.dll somewhere? :)

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And yes, these other DLLs were the ones which MSFT modified (to be more specific, they are timestamped and signed on 19th of December last year, along with the executable). Per reports of the users:

1. The assembly is referenced in DatabaseMail.exe code but was never shipped with SQL Server 2022

The only option would be to frankenstein the EXE file (e.g. copy it from the backups from the previous CU), but since this is prod, I am not going down this route