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One of the big problems that Exchange Administrators have is controlling the size of user's mailboxes. Well never fear help is at hand; with a few simple steps you can have a lot more control.
 

The first thing you will need to consider is, what is an acceptable size for a user's mailbox? The only person who knows what this should be is you; every organization will have a different need. For example, a company who really only sends out simple text message will have a relatively small mailbox limit, whereas a firm of architects who send large drawings to each other will have a large mailbox size.

So, once we have decided what a practical size would be for the user's mailboxes, we can now set these limits. It is possible with Exchange to set these limits on a user by user basis, we can use a policy to set them for a complete mailbox store or we can have a policy that applies to a particular server.

We are going to start looking at how to set them for an individual mailbox.

1.       Open Active Directory Users and Computers.

2.       Right click on the user who you would like to set a mailbox limit.

3.       Select Properties from the menu.
 

Figure 1

4.       Select the Exchange General tab and then pick the Storage Limits button, you will now be presented with the dialogue box shown in Figure 1.

You will notice that the default set is to Use mailbox store default, so if we want to set a limit for this user only we must clear this checkbox.

The three options that are available to use are:

Figure 2

We are going to give our user a warning when their mailbox gets to 15Mb and then stop them from sending mail when they reach 25Mb, so we will configure it as shown in Figure 2. Remember the sizes we enter into the dialog box are in KB (1024Kb = 1Mb).

So, we have now set the limits for this user. Imagine having to do that for 1000 users, well as I said in my intro we have a number of other options open to us when it comes to setting mailbox limits.

Let's say we want to apply a limit to all users who have a mailbox in a particular store, this is quite a simple tasks.

Figure 3
 

1.       Open the Exchange System Manager

2.       Locate the Mailbox store that you would like to apply the limits to (Figure 3).
 

Figure 4
 

3.       Right click and select Properties. Select the Limits tab and you will see the dialogue box shown in Figure 4.

Notice that the options here are very similar to the options that we saw on the individual user's mailbox, but we also have an option to specify when the user will receive the notification messages.

Figure 5

By default the notification messages will be generated at midnight each day, we can customize this to meet our own needs. We can either select a predefined time from the drop down list or click on the Customize button to set our own schedule (Figure 5). Be aware that setting the schedule to occur too frequently will degrade your server performance as it has to check each user's mailbox against the limits you have set.

Now let's suppose you have 10 Mailbox stores spread across 5 Exchange servers and you want to enforce a consistent limit across all of these stores. What we need to do is create a Mailbox Store policy. However, before we can create a Mailbox Store Policy we need to have a System Policy Container.

To create a System Policy Container we need to select an Administrative Group and by default these are not displayed in the Exchange System Manager. To display the Administrative Groups: