Mailbox quotas

A mailbox quota limits the storage assigned to an account. Quotas should correspond to the customer's service plan.

Physical capacity

Mailbox quota totals can exceed practical server capacity if administrators oversubscribe aggressively. Monitor actual disk consumption and retain free-space headroom.

Storage growth

• Monitor active mailbox size.
• Monitor aggregate mail-domain usage.
• Watch mail queues during delivery incidents.
• Account for logs and temporary processing space.
• Plan expansion before free storage becomes critical.