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Effect of too many folders (subfolders) in a mailbox. RRS feed

  • Question

  • Hi,

     

    I have a user on exchange 2007 that has 1 GB mailbox and a total of 10 foilders. By 10 folders I mean the sum of all folders in the mailbox including inbox, sent items, deleted items and cutom personal retention that has few subfolders. There is a business deal being worked on so the user is asked to import a mailbox from a client that has a total of 19800 folders. Yes that is correct, 19800 which a lot of nested subfolders within folders. My question is, what will be the effect of this addition on the performance of the server? What will be affected the most, backup time? Managed folder time taken? etc...

    Are there any specific counters we need to look at just for this case? Note that we may have more of these mailboxes being imported to different users

     

    Thanks

    Tuesday, January 18, 2011 8:26 PM

Answers

  • In addition, you may expect the event 9646 on your server.

    Mapi session "/o=OrgName/ou=Admingroupname/cn=Recipients/cn=Username" exceeded the maximum of 500 objects of type "objtFolder".

    • Marked as answer by emma.yoyo Wednesday, January 26, 2011 1:46 AM
    Wednesday, January 19, 2011 6:21 AM
  • The main issue to watch is the number of items in core folders, such as Inbox, Sent Items, etc, as this can affect server performance.  It doesn't sound like this will be an issue in your case as there are many folders rather than many items in the main folders - but one to check anyway; the recommended limit for Exchange 2007 was 20,000 items per folder IIRC. 

    But you might still like to keep an eye on the mailbox size of course, since adding a lot of items to the mailbox will obviously affect mailbox size.  It could also affect database size, LUN free space, etc - all the obvious stuff really!  If you have current data on how long things take now (like backups and managed folder time)  you can easily compare this once the import has taken place.


    Neil Hobson | Principal Consultant, Silversands | www.msexchange.org/neil_hobson | neilhobson.blogspot.com | twitter @NeilHobson
    • Marked as answer by emma.yoyo Wednesday, January 26, 2011 1:46 AM
    Tuesday, January 18, 2011 8:35 PM
  • In addition to that you may also keen an eye on Catalogue indexing.

    An Exchange 2007 Server Stops Responding to a MAPI Client

    http://technet.microsoft.com/en-us/library/bb676486(EXCHG.80).aspx

    I might be worng, but I remember that some where in one of the KB its mentioned that if you have very huge nested folders in mailbox, you can face RPC diagloue box.

     

    • Marked as answer by emma.yoyo Wednesday, January 26, 2011 1:46 AM
    Wednesday, January 19, 2011 8:34 AM
  • "Creating more top level folders, or subfolders underneath the Inbox and Sent Items folders, greatly reduces the performance impact associated with this index creation."

    White Paper: Planning for Large Mailboxes with Exchange 2007

    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.
    • Marked as answer by emma.yoyo Wednesday, January 26, 2011 1:46 AM
    Tuesday, January 25, 2011 2:18 AM

All replies

  • The main issue to watch is the number of items in core folders, such as Inbox, Sent Items, etc, as this can affect server performance.  It doesn't sound like this will be an issue in your case as there are many folders rather than many items in the main folders - but one to check anyway; the recommended limit for Exchange 2007 was 20,000 items per folder IIRC. 

    But you might still like to keep an eye on the mailbox size of course, since adding a lot of items to the mailbox will obviously affect mailbox size.  It could also affect database size, LUN free space, etc - all the obvious stuff really!  If you have current data on how long things take now (like backups and managed folder time)  you can easily compare this once the import has taken place.


    Neil Hobson | Principal Consultant, Silversands | www.msexchange.org/neil_hobson | neilhobson.blogspot.com | twitter @NeilHobson
    • Marked as answer by emma.yoyo Wednesday, January 26, 2011 1:46 AM
    Tuesday, January 18, 2011 8:35 PM
  • Space is not an issue and the I always keep the number of items issue in mind. I just thought that adding a crazy number of folders like 19800 to one's mailbox may affect how long the mailbox will be scanned for instance, search,etc... I know there is a issue with some third-party handheld devices that do not react very well to a large number of folders in a mailbox. Thanks though for the reply.

    Tuesday, January 18, 2011 8:51 PM
  • In addition, you may expect the event 9646 on your server.

    Mapi session "/o=OrgName/ou=Admingroupname/cn=Recipients/cn=Username" exceeded the maximum of 500 objects of type "objtFolder".

    • Marked as answer by emma.yoyo Wednesday, January 26, 2011 1:46 AM
    Wednesday, January 19, 2011 6:21 AM
  • In addition to that you may also keen an eye on Catalogue indexing.

    An Exchange 2007 Server Stops Responding to a MAPI Client

    http://technet.microsoft.com/en-us/library/bb676486(EXCHG.80).aspx

    I might be worng, but I remember that some where in one of the KB its mentioned that if you have very huge nested folders in mailbox, you can face RPC diagloue box.

     

    • Marked as answer by emma.yoyo Wednesday, January 26, 2011 1:46 AM
    Wednesday, January 19, 2011 8:34 AM
  • "Creating more top level folders, or subfolders underneath the Inbox and Sent Items folders, greatly reduces the performance impact associated with this index creation."

    White Paper: Planning for Large Mailboxes with Exchange 2007

    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.
    • Marked as answer by emma.yoyo Wednesday, January 26, 2011 1:46 AM
    Tuesday, January 25, 2011 2:18 AM