Hi AllI read that the maximum size limit for Exchange Server 2003 SP2 Enterprise databaseis now about 8000 GB,But my questions that is there any limitation for the mailbox size per user, any limitation for the storage group size, and is there a maximum number for the storage groups that I can create within the organization.Thanks all

Here are your answers:1. No limitation on the mail box size. Seen mail boxes of 91 GB and still working good.2. Storage group has no size. Size is always on the database. 3. There is limit of 50 Storage groups that you can create in exch 2007 enterprise (max 50 database stores is limit for stores.).Raj

Hey Raj, the question was on Exchange 2003 and not Exchange 2007. :)With Exchange 2003, you can create a maximum of 4 storage groups each with up to 5 databases for a maximum of 20 databases (assumes you're running the Enterprise Edition of Exchange 2003). IIRC, the maximum size of a database in Exchange 2003 was listed as 16TB (or limited only by hardware) but of course you'd never do that in practice. It was always a good idea to keep E2K3 databases to around 50GB or less, mainly for streaming backup purposes.Neil Hobson, Exchange MVP

My Bad Neil, missed it .Raj

Yes, here is the document for your reference:Comparison between Exchange Server 2003 Standard Edition and Exchange Server 2003 Enterprise Editionhttp://support.microsoft.com/kb/822440For 2007: http://www.microsoft.com/exchange/2007/evaluation/editions.mspx