How can I limit Exchange mailbox size?

A. Exchange comes built in with the ability to limit and notify of quota violations.

To set the limits perform the following:

  1. Start the Exchange Administrator Program
  2. Expand the organisation, then the site and then the servers branch
  3. Expand the server whose quota's you wish to set, select "Private Information Store". Select Properties from the file menu
  4. Select the general tab
  5. You can set a policy for the keeping of deleted items (this is useful if you have users who delete mail they wanted to keep and will save you having to fish out a backup. Be careful of setting the "Don't permanently delete items until the store has been backed up" as if backups are not often this could affect performance badly.
  6. The bottom half of the dialog allows you to set actions for quotas, namely
    - A warning to be issued, e.g. 900 KB
    - Stop the user sending mail, e.g. 1100 KB
    - Stop the user receiving mail, e.g. 1500 KB
  7. Click Apply then click OK

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Individual limits can be set for users by double clicking on them under the Recipients branch and selecting the "Limits" tab. Under "Information Store storage limits" sections unselect the "Use information store defaults" and set explicit values for the user. Useful for your own mailbox ;-)

Now the values for the warning have been configured you must tell the system how often to warn the mailbox owner.

  1. Start the Exchange Administrator Utility
  2. Expand the organisation and site
  3. Expand Configuration
  4. Double click on the "Information Store Site Configuration"
  5. Select the "Storage Warnings" tab
  6. Select the warning level, either never, always (which is every 15 minutes) or at Selected Times.
  7. Click Apply then OK

If a client exceeds the limit they will be given warnings to the effect of

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If the client does not have the helpful Office Assists enabled they will just get a normal dialog box.

A message from the "System Administrator" with the conditions of the mailbox quotas will also be sent:

Your mailbox has exceeded one or more size limits set by your administrator.
Your mailbox size is 1518 KB.

Mailbox size limits:
You will receive a warning when your mailbox reaches 900 KB.
You cannot send mail when your mailbox reaches 1100 KB.
You cannot send or receive mail when your mailbox reaches 1500 KB.

You may not be able to send or receive new mail until you reduce your mailbox size. To make more space available, delete any items that you are no longer using or move them to your personal folder file (.pst). Items in all of your mailbox folders including the Deleted Items and Sent Items folders count against your size limit. You must empty the Deleted Items folder after deleting items or the space will not be freed.

See client Help for more information.

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