Tony Redmond wrote an article about how Microsoft have changed their minds and gradually phased out the unlimited archiving mailbox. The change happened on November 1, 2021, and users can’t to add more information to archive mailboxes “if it pushes the mailbox past the 1.5 TB limit.”

Are you already above 1.5 TB? Probably not much to worry, because Microsoft is likely to make an exception for you. Anyway, if you have such a huge mailbox and an archive, then they have already contacted you to discuss what’s next.

What I found funny is that some 3rd party email archiving vendors think it’s a good occasion to alarm every O365 user about this “serious” issue. Some of them claim that when you pass the 1.5 TB limit, you cannot consider yourself compliant to regulations like FRCP, FOIA, and indeed, it might be an issue.

However, I think it’s more like a FUD. While it’s certainly true that a 3rd party email archive is immune to the 1.5 TB per user archive quota in O365 (provided that you have enough storage allocated for the archive), not to mention that I personally believe that a 3rd party email archiving solution is much more comprehensive and performs better than O365’s archive mailbox.

We know by now that no storage can be big enough for users. Still, I think this change affects very few users, most of them won’t ever come close to the 1.5 TB limit. Tony Redmond estimates in his article that “using the 1 GB/day limit, the 1,536 GB will take 4.2 years to fill, or 7.68 years at a more reasonable 200 working days per year.”

Despite I tend to feel that users send everything in email, including office documents, funny images, etc, most sources on the net say that the average email size is only 75 kB. Taking this number you need to get ~13,000 emails every workday to match the above 1 GB emails. Quite unlikely for the most of us.