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Will mailbox size stay the same when migrating to Exchange Online? RRS feed

  • Question

  • I have a mailbox in Exchange 2010 that has grown to about 15Gb over the last 10 years. If I migrate this to Exchange Online, can I expect that it will consume roughly the same amount of space? I'm worried about that 25Gb limit, and I DO NOT want to have to delete any of my old messages.

    Also, can someone confirm what I read elsewhere that Exchange Online does not impose any limits on how long deleted items are retained?

    Thank you!

    Wednesday, July 2, 2014 11:24 AM

Answers

  • Exchange online has a 50GB mailbox limit now. It should no more be 25GB.

    The mailbox size might increase a little bit when moved to O365. But it will not go to a huge extent. From Exchange 2010 to Exchange online (running Exchange 2013, this should be minimal although I cant confirm how big it will be for sure).

    I would recommend a way. Keep everything copied on to one of the PSTs. If you notice any issues, you anyway have a backup in your PSTs.

    Items deleted from the deleted items will stay there for 14 days by default in recover deleted items and you can change that to up-to 30 days.

    • Marked as answer by EdwardLee Thursday, July 3, 2014 12:47 AM
    Wednesday, July 2, 2014 12:11 PM

All replies

  • Exchange online has a 50GB mailbox limit now. It should no more be 25GB.

    The mailbox size might increase a little bit when moved to O365. But it will not go to a huge extent. From Exchange 2010 to Exchange online (running Exchange 2013, this should be minimal although I cant confirm how big it will be for sure).

    I would recommend a way. Keep everything copied on to one of the PSTs. If you notice any issues, you anyway have a backup in your PSTs.

    Items deleted from the deleted items will stay there for 14 days by default in recover deleted items and you can change that to up-to 30 days.

    • Marked as answer by EdwardLee Thursday, July 3, 2014 12:47 AM
    Wednesday, July 2, 2014 12:11 PM
  • According to the Exchange 2013 release notes the apparent size of mailboxes migrated from legacy versions could increase by 30-40%.

    http://technet.microsoft.com/en-us/library/jj150489(v=exchg.150).aspx

    However this will not cause you any issue as the quota has been increased to 50GB per mailbox.

    Thursday, July 3, 2014 10:52 AM