Lots of ESM errors in the Eventlog.
Checking the log mentioned in the Eventlog message shows the following:
07:29:32 DEBUG: BEGIN WalkMessage(Re:Your Message) in folder 'Deleted Items'
07:29:32 DEBUG: BEGIN GetCheckSum()
07:29:32 DEBUG: calling GetProps for property 007D001F
07:29:32 ERROR: GetProps:
07:29:32  Unspecified error
07:29:32 Error: The client operation failed.
07:29:32 Component: Microsoft Exchange Server Information Store
07:29:32 Low level error: 80004005
07:29:32 Context: 00000501
The message has been deleted from Exchange.
Archive manager exports all deleted messages. It exports both hard deleted (Shift-Delete option) messages and soft deleted (via deleted items folder) ones.
There are two deletion types, logical and physical.
The logical deletion is when the item is deleted from the client with Outlook. It does not matter if it was deletion from Deleted Items folder or using Shift-Delete option. The item is marked in the store as deleted, and hidden from the client. But it still resides on the mailbox store. This item is also marked for the number of days that it is to be retained before the Information Store Maintenance Agent does the physical deletion.
The physical deletion is the actual removal from the store. So Archive Manager can only see and export messages when they are deleted logically.
Add the following configuration editor entries:
Show Soft Delete Messages | False
Exchange Store Manager Failed Message Max Retries | 2
Restart the Archive Exchange Store Manager Service.