Microsoft launched the MailItemsAccessed audit event (to capture when email is opened) in January, reversed the roll-out in April, and now might restart sometime in Q3. It’s an odd situation that isn’t really explained by a statement from Microsoft. Are they going to charge extra for this audit event? Will they be analyzing the events? Or does Office 365 capture too many mail items accessed events daily?
On May 7, Microsoft eventually fixed a truncation bug that affected group events (creation, add member, etc.) ingested into the Office 365 audit log. The fix took far too long coming and the overall response is certainly not Microsoft’s finest hour. Audit events, after all, are pretty important in compliance scenarios and it’s not good when those events are incomplete.
Announced in January, paused in March – that’s the fate of the MailItemsAccessed audit record generated by Exchange Online for the Office 365 audit log. Microsoft found some problems that they are fixing, which is good (because you want audit data to be reliable). And when the fixes are available, the deployment of the new audit record will restart.
In one of those interesting (but possibly worthless) facts discovered about Office 365, we find that audit records are captured for Teams compliance records written into Exchange Online group mailboxes. The Search-UnifiedAuditLog cmdlet reveals details that we can interpret using some techniques explained in Chapter 21 of the Office 365 for IT Pros eBook.
Exchange Online now captures session identifiers in its mailbox and admin audit records that are ingested in the Office 365 audit log. That’s interesting and useful, but how do you access and interpret this information on a practical level?