5.5. Controlling Mailbox Size Limits
Problem
You want to apply mailbox size limits to users, groups, or organizational units, but Exchange only lets you set them on servers, mailbox databases, or the Exchange organization.
Solution
Using a graphical user interface
To set mailbox limits on an individual user, do the following:
Log on to any machine in your domain that has the Exchange management tools installed.
Open the ADUC snap-in (Users and Computers.msc).
Locate the account whose mailbox limits you want to change.
Right-click the target account or group and select Properties.
The account properties dialog will appear. Switch to the Exchange General tab (remember, you'll only see this if you're editing a mail-enabled object and if you've installed ESM on the machine from which you're running the snap-in).
Click the Storage Limits button; the Storage Limits dialog box will appear.
Uncheck the Use mailbox store defaults button.
Select the desired combination of warning, prohibit send, and prohibit send/receive limits and sizes.
Click OK.
Using a command-line interface
To set a user's quota limits from the command line, use
exchmbx with the -quota switch:
exchmbx -b<userDN> -quota <warningLimit>:<prohibitSendLimit>:<prohibitReceiveLimit>
You specify the quota limits in kilobytes, using ordinary
integers (e.g., 100000:120000:125000 to specify limits of
100 MB, 120 MB, and 125 MB, respectively). To get mailbox send and
receive limits for multiple users, you can use the csvde
command to generate ...