Microsoft Retreats From 1TB Limit for Auto-Expanding Archives – For Now

Last November, just as everyone was getting ready for the opening of the Microsoft Ignite conference in Orlando, Microsoft dropped a bomb on the Exchange community by updating the service description for online archiving to set a 1 TB limit for archive mailboxes. At the time, Microsoft said

“The unlimited archiving feature in Office 365 (called auto-expanding archiving) provides up to 1 TB of storage in archive mailboxes in Exchange Online.”

Calling something “unlimited” while specifying a limit was pretty silly, but the lack of communication was the biggest issue. No formal announcement was made, probably because those responsible for the decision realized the howls of derision that might have erupted from the community. Not to mention the hard questions that Microsoft representatives might have had to handle at Ignite sessions.

Conversations and Communication

In any case, several hard conversations occurred at Ignite, notably between the Office 365 MVPs and the Exchange development group. It was pointed out that making a major reversal in strategy by imposing an arbitrary limit and saying nothing about it wasn’t a good way to build customer confidence. A terabyte is a lot of information, especially in a mailbox, but setting limits without explaining why this is a good thing or how many mailboxes are affected undermines Microsoft’s message to customers that their data is best when kept in the cloud. Preferably Microsoft’s cloud.

The Business of Archiving

On the other hand, as I noted at the time, Exchange Online is part of the Office 365 business, and offering to store as much information as tenants care to import into archive mailboxes is probably not a good thing on either a technical or business level. From the technology perspective, you could imagine that a single massive archive mailbox might fill a complete mailbox database, which could create some problems in dealing with such a beast.

The economics of making huge amounts of storage available for tenants to fill with archive data is also uncertain, even at the price that Microsoft pays to purchase and operate storage in its Office 365 datacenters. In short, a case can be argued to set a limit for the automatic expansion of archive mailboxes.

A Reasonable Limit

Setting that limit at twenty 50 GB “chunks” chained together to form a 1 TB archive mailbox is reasonable. There are archive mailboxes larger than this, but not many. And once a limit is set and publicized, tenants will know what they have to work with and can stay within the limit.

A New Communications Failure

Microsoft failed to communicate with Office 365 tenants in November. And now, without saying anything to customers (again), they’ve retreated from their previous position in a new version of the service description that says:

“The unlimited archiving feature in Office 365 (called auto-expanding archiving) provides additional storage space in archive mailboxes. Each Exchange Online Archiving subscriber initially receives 100 GB of storage in the archive mailbox. When auto-expanding archiving is turned on, additional storage space is automatically added when the 100 GB storage capacity is reached.”

No mention of a 1 TB limit is visible. Nothing much changes because the previously announced limit was not implemented in software. It was an aspiration that such a limit should be in place, but no code was ever written to impose the limit or issue warnings as archive mailboxes grew, perhaps when an archive mailbox added the 20^th chunk to its set. No administrative interface was created either to allow tenant administrators to see the state of large archive mailboxes or receive warnings through any of the multiple admin portals where archive mailboxes show up in Office 365. And PowerShell, the key to Exchange administration, was not updated either. In short, November’s update was a paper exercise.

A Real Limit for Archive Mailboxes is Coming

However, I suspect that the writing is on the wall for ever-expanding archives. We will hear about this topic again after Microsoft has worked through the ins and outs of the decision and created a proper communications and implementation plan. Tenants will be told, administrators will be given the tools to manage large archive mailboxes, and the limit will be enforced. Maybe not immediately by software updates, but it will happen.

I hope the folks behind this decision understand the errors they made before the announcement appeared in November. It would be sad if they repeated the error in the future and imposed a (real) limit without warning. We can but hope.

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More information about the management of Exchange Online archive mailboxes is available in Chapter 5 of the Office 365 for IT Pros eBook. Given communication like in this example, you need a strong independent source for news about Office 365.