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Restricting mail storage on an Exchange server

In this tip from "15 tips in 15 minutes: Managing recipients and distribution lists," you'll gain essential knowledge of mail storage on an Exchange server. You'll learn how to set appropriate mailbox sizes, steps to creating new system policies, and local archiving options to keep your users from taking advantage of the storage system.

Under normal circumstances, you want users to have as much access to your messaging system as possible. Circumstances arise, however, when users take advantage of the system by sending messages with huge attachments to hundreds of users or by storing every bit of email they've received since the start of the Bush administration. (That's George H., not George W.)

You are reading tip #9 from "15 tips in 15 minutes: Managing recipients and distribution lists," excerpted from Chapter 5 of the book Learning Exchange Server 2003, published by Addison-Wesley Professional.
In the first Matrix movie, the agent program named Smith whines to Morpheus that he, Smith, has tired of the Matrix and yearns to return to wherever programs live when they don't torture human spirits. Smith compares humanity to a virus, saying, "You move to an area and you multiply and multiply until every natural resource is consumed. The only way you can survive is to spread to another area."

I'm sure you'll agree that Smith had an ax to grind and therefore didn't exactly have an objective opinion, but to tell you the truth, when I look at storage on an Exchange server, I'm tempted to think that Smith stumbled on a bit of truth. No matter how much storage you provide to users, they quickly use it up and cry for more. If you try to draw a line and say, "You get this much storage and no more," users go around you and cry to executive management or buy their own servers and sneer at you in the lunchroom.

Putting the brakes on storage expansion

Users don't appreciate, of course, that the cost of storage starts only with the spindles and RAID cages. You have to back up the store every night and restore it if something goes wrong. If you have more than 16GB of data in your Exchange store, you have to invest in Exchange Enterprise Edition, at a $2,500 price differential. And above all, you have to address concerns about stability and reliability and service level agreements when you have a server with a huge store.

So, for better or worse, in spite of their bellyaching and complaining, the time eventually comes when you have to put limits on the size of your users' mailboxes. The sooner the better, really, before they get spoiled.

You can find the worst offenders by scanning down the list of mailbox sizes shown in ESM. Drill down to a Mailbox Store and see the sizes and item count in the right pane of the console, as shown in Figure 5.40.

Figure 40
Figure 5.40 Mailbox sizes displayed in ESM. Click the Size column heading to sort the largest mailboxes to the top.. (Click on image for enlarged view.)

When setting mailbox size limits, select a maximum size that accommodates average use while not overloading your storage capacity. If you have 200 users and a single Exchange Standard Edition server, you would need to impose a quota of 80MB per user to stay under the maximum storage limit of 16GB. If you invest in Enterprise Edition, calculate your quotas based on the maximum size of the databases you want to back up and restore.

There are a lot of ways to decide how to apportion storage. For example, you could use a economist's approach:

  • Capitalistic. Track the storage consumed by a set of users and charge them for it. To keep data growth in check, economically punish any department that abuses your storage guidelines. "Sure, we'll give you another 16GB of storage. It will cost you $5,000."

  • Socialistic. Follow the dictum, "To each according to his need." The IT organization purchases spindles and backup equipment out of its own budget; then carves out quotas based on the total available storage and takes requests from departments who can prove they need more than their standard allotment. (Leaving chocolate chip cookies and fresh Arabica coffee beans at the entrance to the server room helps to get an allotment increase.)

Storage policies

You can assign storage limits on individual mailbox stores, but it makes more sense to set a System Policy and then assign the policy to the mailbox stores within an Administrative Group.

For example, if you have several Enterprise Edition servers, you can create multiple mailbox stores and use them to categorize users by mailbox usage. You can have a high-quota mailbox store for users who insist on having 500MB mailboxes, you can have moderate-quota stores for users who are happy with a 25MB limit, and you can have low-quota stores for users who infrequently use the messaging system and need only a 5MB mailbox. You would then create System Policies to enforce these limits and apply the policies to the appropriate mailbox stores.

To create a System Policy to set storage limits, proceed as follows:

  1. Launch ESM and drill down to the Administrative Group you want to manage.

  2. Right-click the System Policies icon and select New -> Mailbox Store Policy from the flyout menu. This opens the New Policy window.

  3. Check the Limits option under Property Pages and click OK. This opens a Properties window where you can enter the name you want to apply to the policy. I'll use the name Moderate Quota User Storage Limits.

  4. Select the Limits (Policy) tab, as shown in Figure 5.41. The policy in the example issues an email warning to the user when the total size of the user's mailbox store exceeds 25MB. The policy prohibits the user from sending messages after exceeding 35MB and essentially turns off the mailbox after exceeding 40MB.

    Figure 41
    Figure 5.41 Mailbox size limits imposed by storage policy.

  5. Click OK to save the policy. It will not affect any storage yet. You must first link the policy to a mailbox store before it takes effect.

  6. Right-click the new policy in ESM and select Add Mailbox Store from the flyout menu.

  7. Use the object picker to select the store or stores from your Administrative Group that you want to manage.

  8. Click OK to save the change. If you want to apply the policy settings immediately, right-click the policy icon in ESM and select Apply Now from the flyout menu.

Of the three escalation options, prohibiting incoming mail receipt is the most drastic. Some organizations don't like to block incoming mail for any reason because an important message might get bounced. For example, if a user has exceeded the upper storage limit and has been blocked from receiving messages, a sender will get a NDR similar to the one shown in Figure 5.42.

Figure 42
Figure 5.42 NDR sent to user when recipient's mailbox has exceeded quota.

The user gets a warning that the storage limit has been exceeded, but does not get notified when individual messages begin bouncing back to the sender. Before implementing this policy, it's a good idea to get specific approval from management. Your manager's mail could get bounced.

Local archiving

It doesn't do any good to have quotas if you don't give users a place to put their overflow messages. The Exchange server does not have an offline storage feature for old items. Instead, each Outlook recipient keeps a repository of older messages in an archive.

The Outlook archive consists of a PST file called Archive.pst by default. This file contains messages placed there by an Autoarchive service that runs periodically within Outlook. I'm sure you've seen the popup message that asks, "Do you want to archive your messages now?"

To change the autoarchive settings, go to Tools -> Options on the main menu and then select the Other tab. Look for the second set of options, labeled AutoArchive, shown in Figure 5.43.

Click the AutoArchive button. This opens the AutoArchive settings window, as shown in Figure 5.44.

Figure 43
Figure 5.43 Outlook options showing AutoArchive button (second section).

Figure 44
Figure 5.44 Outlook configuration for AutoArchive feature.

Every 14 days (the default interval), the autoarchive process cleans out old messages from the user's mailbox and places them into the archive.pst file. This has several ramifications for desktop support technicians:

  • Archive.pst resides in the user's profile. If the technician deletes the profile, all archived messages go bye-bye.

  • The archive file resides in a special section of the user's profile called Local Settings. This section does not form a part of a roaming profile. This means that roaming users see different archive contents depending on the machine they use.

  • Outlook displays archived items in a separate folder, so users of older Outlook clients who do not have Folder View enabled do not see the archive folder and think their mail has disappeared.

The archive process in Outlook copies an item to Archive.pst and then deletes the archived item directly from the folder where it resides. This so-called "hard" delete means that the item does not pass through the Deleted Items container. As you'll see in a bit, you can recover hard deleted items, even when deleted via archiving, if you get to them during the retention interval, seven days by default.

The option to Prompt Before AutoArchive Runs keeps the user informed of the archiving process, but it also provides the user with the option to say "No, Don't Archive." By archiving in the background, you are more likely to achieve 100 percent compliance with your storage policy. The user can still access the archived messages, but they need to look in the archive folder. This will require a little end-user education. Make sure that any archiving/deletion policy you implement adheres to corporate information retention-compliance issues.

15 tips in 15 minutes: Managing recipients and distribution lists

 Home: Introduction
 Tip 1: Exchange security groups
 Tip 2: Group membership expansion
 Tip 3: Managing Exchange group email properties
 Tip 4: Exchange 2003 Query-Based Distribution Groups
 Tip 5: DSAccess for Exchange
 Tip 6: DSProxy for Exchange
 Tip 7: Managing Exchange recipient policies
 Tip 8: Exchange Recipient Update Service and proxy addresses
 Tip 9: Restricting mail storage on an Exchange server
 Tip 10: The Exchange server mailbox management service
 Tip 11: Blocking a user's email access
 Tip 12: Accessing another user's mailbox in Outlook
 Tip 13: Exchange mail retention
 Tip 14: Managing recipients with system policies
 Tip 15: Managing recipients with Global Settings

This chapter excerpt from Learning Exchange Server 2003 by William Boswell is printed with permission from Addison-Wesley Professional, Copyright 2004. Click here for the chapter download or to purchase the book.

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