Capturing “Crucial” Office 365 Audit Events Requires E5 Licenses

Microsoft has released information about high-value Office 365 audit events and audit event retention policies. Both are part of a Microsoft 365 Advanced Audit offering. The MailItemsAccessed event is the first high-value audit event (we can expect more) and the retention policies are used to purge unneeded events from the Office 365 audit log.

What’s Happening with the MailItemsAccessed Audit Event

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?

Microsoft Halts Deployment of MailItemsAccessed Audit Records

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.