Hello All,I was curious as to some of the best practices for storing mailbox databases and storage groups. IE:Should I use one Storage group for my entire organization or if I have seperate AD Sites use seperate mailbox db or storage group fore each. Should I then break mailbox databases down even further? Maybe by department?

Hey Joshua, I would suggest separate by mailbox quota instead of department or AD Site so you can do capacity planning properly according to the size calculation formula available in below article. Mailbox Server Storage Design http://technet.microsoft.com/en-us/library/bb738147.aspx Some Recommendations for Exchange 2007: ~ Plan 1 DB per storage group. ~ Keep the mailbox database size up to maximum 100GB and if you have any continuous replication (LCR or CCR) enabled on storage group level, maximum up to 200GB. So do proper capacity planning as per article given above.Amit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com

Well, since Amit has given the recommended size for mailbox database, I would like to tell you how to determine the maximum number of users per mailbox store in the Exchange Server 2007: 1. There are several values we need to get at first: a. Set the Mailbox Quota for users b. Calculate the size of White Space for one mailbox, its about [The average amount of mail send/receive per mailbox per day] Notes: White Space can be oversized if online maintenance isnt completed properly c. Calculate the size of Mailbox Dumpster, its about [Average size of each soft-deleted item X Amount of mail send/receive per mailbox per day X Deleted Item Retention Setting (14 days by default)] Notes: Its usually 5 percent of the Mailbox Quota 2. Now, its time put all values above together to obtain our Actual Mailbox Size, the formula for one mailbox is: Mailbox Quota + White Space + Mailbox Dumpster 3. After we know the actual mailbox size, we can base on maximum recommended database size from Amit to calculate the maximum number of users that one mailbox store can stand Other resource you may need: Exchange 2007 Mailbox Server Role Storage Requirements Calculator