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Determining the best mailbox quota size for your users

We recently imposed a 100 MB quota on mailboxes. Some people want more space. Should we give them 200 MB or 250 MB? What do other companies do? Is there a better solution to limiting mailboxes?
There's really no standard for mailbox quotas -- every company does it differently. You may want to get an Exchange reporting/analysis solution in-house to get some more details on how your Exchange infrastructure is being used from a capacity perspective. In other words, have a look at average message sizes being transmitted internally and to the Internet, how many people are sitting at or above their quotas, etc. I recommend increasing the quota in small increments and on an as-needed basis. I'd classify your users into two or three groups based on how much they use e-mail in their jobs. Then set quotas accordingly.

You may want to bump your executives up to 250 MB while keeping average users at 150 MB, and even limiting others to 100 MB if they're not heavy e-mail users.

If you give your end users a larger mailbox today, it'll be pretty well impossible to reduce the limit in future. Keep tight control over mailbox quotas and only increase them if demand warrants, and only for specific users. Otherwise you risk having massive database bloat (and associated storage costs) due to the many "packrats" in your environment.


The one comment I would like to make is these quotas force PST usage or make people sign up for free Google or Yahoo 1 GB mailboxes. Disk space is cheap and expandable in today's world. With e-mail being mission-critical and mobility devices on a massive rise, this answer isn't realistic. (If you want to get into compliancy, ownership and archiving, that's a whole new ball of wax.) We are a service and if we don't meet our customer's needs, someone else will. That why IT departments crumble; they forget their place in the business model.

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