I'm not sure if this is the right forum but my question is related to Exchange but more on Outlook. My understanding is that mailboxes such as pst and ost that exceed 2GB size may experience performance issues. As stated in this article. http://support.microsoft.com/kb/932086 I'd like to know what is the actual mailbox size limit on what Outlook 2003 /2007 can hold on a pst or ost. Can someone send me a link or documentation where I can review this?Is it different limitations for 2003 or 2007. Another example what if a persons mailbox is 15GB ( is that even possible?), will it affect their access to the Exchange server or does it mostly affect mail client programs? Thanks for any of your responses!

ost/pst over 2GB's will work in this day and age, but really that is a sensible limit for a mailbox size. Is it possible to have a 15GB mailbox size? Abosolutely. Is it smart? Not really, as your client machine will have a 15gb OST file. I've got users with mailboxes as big as 5GB and their OST files really tax their laptops.

Don't use cached mode on a mailbox over 1.5GB or it will function very poorly. In online mode you can easily go higher but it is not recommended as there will be adverse effects to the Exchange Server.