TotalMailboxSize and BytesTransferred RRS feed

  • Question

  • Hi all,

    I have an issue regarding mailbox moves from Exchange 2010 to Exchange 2013. I moved a mailbox and checked statistics on completion. I know that mailboxes can grow up to 30-40% on migration, but the statistics tell me much more.

    There was TotalMailboxSize 923MB and BytesTransferred 2.53GB. I wonder, what's the cause. Mailbox database quota was default by 2.3 GB - so the user wasn't able to send mails anymore. What's the cause for such a size increasement?


    Wednesday, October 22, 2014 2:17 PM


  • Hi,

    I searched and found that the reported size of the mailboxes will increase around 30% to 40% after moving mailboxes normally, but sometimes it may increase around 300%. It is not controlled.

    Please use the Get-MailboxStatistics command to check the total item size in mailbox, after you migrate to Exchange 2013.

    And before you migrate mailbox to Exchange 2013, please check the report of mailbox size statics.

    Best regards,

    Belinda Ma
    TechNet Community Support

    • Edited by Belinda Ma Thursday, October 23, 2014 7:47 AM
    • Marked as answer by Belinda Ma Monday, November 3, 2014 2:28 AM
    Thursday, October 23, 2014 7:47 AM