In recent months we’ve been receiving quite a few questions from customers regarding auto-expanding archives. I’d like to clear up some of the misconceptions and answer some of the most frequently as...
Updated Jul 01, 2019
Version 2.0
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SimonasPikelis, while the PST export and import will work, it's really painful.
My experience is that a remote move won't even start if the archive is oversize. There's no way I know of to move an archive mailbox that's over 100 GB to Exchange Online using a remote mailbox move. If you provision a separate mailbox in Exchange Online, then use third-party tool like MigrationWiz to migrate the content, the oversize archive migration will fail. If you wait a short while for the limit to be extended by the 10 GB, you can restart the migration, but it'll fail again when it reaches 110 GB. At that point you must wait for up to 30 days for the split to occur, at which point you can restart the migration. Repeat until all the data is migrated.
The total mailbox size isn't relevant. The primary mailbox must be below 100 GB and the archive mailbox must be below 100 GB.
Maybe things have changed since I last did this. If so, I'd be interested in hearing about it.