Wednesday, July 29, 2009

Largest Exchange Mailbox?

I have been working with Microsoft Exchange Server since v5.0. During all those years and versions, I have seen mailboxes of all sizes. I have seen users with a couple of 4GB pst files. The largest mailbox I have ever seen on a system was around 8GB, and I used to think it was huge... until recently. I was performing a "site assessment" for a client and was collecting information about their Exchange Server 2003 environment. Since the disk space was a non-issue for the client, there were no quotas defined at the mailbox size level. I opened up the Mailboxes view in ESM and sorted the mailboxes by size to see the top 10 mailboxes and I got perplexed. I looked at the screen again, and asked the IT Manager if I was seeing right. Here's what I saw:

(The names of the users have been blurred to protect the innocent.)

So now the largest single mailbox I have ever seen is 27GB. How about you? What is the largest mailbox size you have ever witnessed? Please share your experiences and thoughts using the "Comments" link below.


Anonymous said...

I manage Exchange 2007 system for our company.
We have only about 100 users but they are all heavy users. Our largest mailbox is currently 60+GB with a 47GB in closa second.
Down the tree we have about 12 boxes between 20 and 30GB.
When I joined the company they were on a single mailstore on Exchange 2003!
It was 250GB!! The first week I was here it crashed and took 5 days to repair it so it would mount! Since upgrading to 2007 shortly therafter and spreading the users over 25 storage groups with a total DB size of approx 750GB we have had zero issues. 2007 is a godsend to anyone facing these kinds of challenges.

Anonymous said...

Our average mailbox size is about 10GB. The largest being 52GB. Many are in the 30's and 40's. I think this is how law firms are...

Dave-G said...

not to beat a dead horse on this topic, but we just found a mailbox in a company we bought that was 355 GB. It only has 308K items though (which isn't even close to a few others on that server).
I'm pretty sure that's the world record.