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mailbox and archive mailbox size limit RRS feed

  • Question

  • I need help to verify my knowledge.  

    1. For Exchange 2016 on-prem both mailbox and archive mailbox size is "unlimited".  Technically they are limited to mailbox database size 16 TB.  

    2. For office 365 with E3 or E3 the online mailbox is limited to 100 GB, the archive mailbox is "limited" to 100 GB.  But with auto expanding enabled it could add another 100 GB archive mailbox once the first 100 archive mailbox is full, go on and on, and no limit.

    3. Exchange 2016 on-prem with online archiving (standalone plan 2).  It will be used for archiving only.  The archive mailbox will be 100 GB initially and auto-expand to unlimited.

    Am I correct for these 3 items?

    BTW.  If I disabled the archive mailbox feature will those archived emails be moved back to user's primary mailbox or become in accessible? 

    Thanks in advance.


    Monday, June 24, 2019 10:30 PM

Answers

  • "1. For Exchange 2016 on-prem both mailbox and archive mailbox size is "unlimited".  Technically they are limited to mailbox database size 16 TB."

    Unlimited in this case means "Not limited by mailbox quotas" not "there is no limit to mailbox size," but yes, you are correct.

    "2. For office 365 with E3 or E3 the online mailbox is limited to 100 GB, the archive mailbox is "limited" to 100 GB.  But with auto expanding enabled it could add another 100 GB archive mailbox once the first 100 archive mailbox is full, go on and on, and no limit."

    Also correct. However, it's important to note that the mechanism that expands the archive mailbox is automated. Once the Archive mailbox reaches 90% utilization, additional space is partitioned and once the mailbox reaches maximum size, a new folder is created to hold mailbox data in that additional space. Physically, an archive mailbox can be found in chunks across any number of disks in any number of datacenters. This functionality, however, causes some issues in that searches are limited to each folder or "chunk" of data provisioned for the archive mailbox.

    "3. Exchange 2016 on-prem with online archiving (standalone plan 2).  It will be used for archiving only.  The archive mailbox will be 100 GB initially and auto-expand to unlimited."

    Also correct.

    " If I disabled the archive mailbox feature will those archived emails be moved back to user's primary mailbox or become in accessible? "

    To my knowledge, Disabling the archive mailbox will result in the archive mailbox being "Disconnected." Email that is in the archive will remain in the archive until restored to a regular mailbox or the archive is reconnected to the mailbox.

    If, at the time of disconnection, the archive mailbox falls under an ediscovery hold or litigation hold, that data will remain in a disconnected state until the hold expires or is removed. Disconnected mailbox data can be reconnected at will, but until reconnected it will be inaccessible. The only exception to that is eDiscovery/content searches, which will include all disconnected mailbox content.

    Monday, June 24, 2019 11:10 PM
  • Here are some detail information about it:

    Mailbox storage limits 

    Disable an archive mailbox 

    Regards,

    Kyle Xu


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.

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    • Marked as answer by ChrisD0919 Wednesday, June 26, 2019 3:57 AM
    Tuesday, June 25, 2019 5:27 AM
  • Yes, each chunk can be provisioned on different storage devices anywhere in the cloud region where your data is stored.

    Searching an expanded archive mailbox is very wonky...If you perform a search in outlook that includes all mailboxes as the source, the expanded archive folders can't be included in the search because the "chunks" exist on different storage devices that are managed by different Exchange servers, which have different search catalogs. In order to search data in an expanded archive (at the moment, this may change), the original storage of the archive can be searched with the All Mailboxes search, but each expanded chunk requires the user to click on the folder associated with that chunk and search it specifically before it will show results.

    This functionality is due to the inherent nature of cloud-based distributed storage. They can't determine in advance how much storage you will use beyond the original 100GB. That 100GB can be provisioned and blocked off easily, but the next chunk of data can't be assigned to the same physical storage as the original archive, because the space where the original archive is stored may already be full or fully provisioned. So it has to go somewhere else. Likewise, the next chunk can't be assigned to the same physical storage as either other piece of the mailbox, so it has to go to another storage location. Make sense?

    • Marked as answer by ChrisD0919 Friday, June 28, 2019 5:11 AM
    Wednesday, June 26, 2019 1:35 PM

All replies

  • "1. For Exchange 2016 on-prem both mailbox and archive mailbox size is "unlimited".  Technically they are limited to mailbox database size 16 TB."

    Unlimited in this case means "Not limited by mailbox quotas" not "there is no limit to mailbox size," but yes, you are correct.

    "2. For office 365 with E3 or E3 the online mailbox is limited to 100 GB, the archive mailbox is "limited" to 100 GB.  But with auto expanding enabled it could add another 100 GB archive mailbox once the first 100 archive mailbox is full, go on and on, and no limit."

    Also correct. However, it's important to note that the mechanism that expands the archive mailbox is automated. Once the Archive mailbox reaches 90% utilization, additional space is partitioned and once the mailbox reaches maximum size, a new folder is created to hold mailbox data in that additional space. Physically, an archive mailbox can be found in chunks across any number of disks in any number of datacenters. This functionality, however, causes some issues in that searches are limited to each folder or "chunk" of data provisioned for the archive mailbox.

    "3. Exchange 2016 on-prem with online archiving (standalone plan 2).  It will be used for archiving only.  The archive mailbox will be 100 GB initially and auto-expand to unlimited."

    Also correct.

    " If I disabled the archive mailbox feature will those archived emails be moved back to user's primary mailbox or become in accessible? "

    To my knowledge, Disabling the archive mailbox will result in the archive mailbox being "Disconnected." Email that is in the archive will remain in the archive until restored to a regular mailbox or the archive is reconnected to the mailbox.

    If, at the time of disconnection, the archive mailbox falls under an ediscovery hold or litigation hold, that data will remain in a disconnected state until the hold expires or is removed. Disconnected mailbox data can be reconnected at will, but until reconnected it will be inaccessible. The only exception to that is eDiscovery/content searches, which will include all disconnected mailbox content.

    Monday, June 24, 2019 11:10 PM
  • Here are some detail information about it:

    Mailbox storage limits 

    Disable an archive mailbox 

    Regards,

    Kyle Xu


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.

    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    • Marked as answer by ChrisD0919 Wednesday, June 26, 2019 3:57 AM
    Tuesday, June 25, 2019 5:27 AM
  • Kyle,

      Thanks for the answers.  For "Physically, an archive mailbox can be found in chunks across any number of disks in any number of datacenters. This functionality, however, causes some issues in that searches are limited to each folder or "chunk" of data provisioned for the archive mailbox." can you provide more details? 

    Are you saying that the additional archive mailbox (O365) could use disk space on multiple disks at anywhere?  And what do you mean "limited to each folder or chunk of data provisioned"?  If I understand correctly, the search will randomly pick up only one folder or chunk data on a disk, not from ALL folders or chunks from ALL disks.  Correct?

    Thanks,

    Wednesday, June 26, 2019 4:11 AM
  • Where do you find this description? Or it just your thought?

    Regards,

    Kyle Xu


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.

    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    Wednesday, June 26, 2019 9:04 AM
  • Yes, each chunk can be provisioned on different storage devices anywhere in the cloud region where your data is stored.

    Searching an expanded archive mailbox is very wonky...If you perform a search in outlook that includes all mailboxes as the source, the expanded archive folders can't be included in the search because the "chunks" exist on different storage devices that are managed by different Exchange servers, which have different search catalogs. In order to search data in an expanded archive (at the moment, this may change), the original storage of the archive can be searched with the All Mailboxes search, but each expanded chunk requires the user to click on the folder associated with that chunk and search it specifically before it will show results.

    This functionality is due to the inherent nature of cloud-based distributed storage. They can't determine in advance how much storage you will use beyond the original 100GB. That 100GB can be provisioned and blocked off easily, but the next chunk of data can't be assigned to the same physical storage as the original archive, because the space where the original archive is stored may already be full or fully provisioned. So it has to go somewhere else. Likewise, the next chunk can't be assigned to the same physical storage as either other piece of the mailbox, so it has to go to another storage location. Make sense?

    • Marked as answer by ChrisD0919 Friday, June 28, 2019 5:11 AM
    Wednesday, June 26, 2019 1:35 PM
  • Hi Adam,

       Thanks for the explanation.  You made it very clear.

    Friday, June 28, 2019 5:14 AM