Effect of too many folders (subfolders) in a mailbox.
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
January 18th, 2011 3:32pm

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
Free Windows Admin Tool Kit Click here and download it now
January 18th, 2011 3:40pm

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.
January 18th, 2011 3:57pm

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".
Free Windows Admin Tool Kit Click here and download it now
January 19th, 2011 1:21am

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.
January 19th, 2011 3:34am

"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 http://technet.microsoft.com/en-us/library/cc671168(EXCHG.80).aspxPlease 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.
Free Windows Admin Tool Kit Click here and download it now
January 24th, 2011 9:19pm

This topic is archived. No further replies will be accepted.

Other recent topics Other recent topics