Engmail -- the Engineering Faculty e-mail server


About engmail

Configuring Clients
Spam rejection
Quota restrictions
Mail Options
Statement on Use

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Engineering Computing

Quota Restrictions

Mail arriving for an engmail user is stored in an incoming mailbox, or "Inbox," where it waits for the user to read it. Quotas are applied to restrict the amount of space available for (i.e. the amount of mail in) a user's Inbox. This helps ensure that space will be available for all users, and reduces the chance that mail service can be interrupted by careless users, or malicious "mail-bombers."

Quotas are set on an individual basis, based on broad user groups. They may be altered for users with exceptional needs. Typical default quotas are as follows:

User Group Hard Quota Soft Quota Grace Period
All as of February 18 2007 1 gigabyte 1000000000 bytes 14 days

Hard Quotas

The Hard Quota is the absolute maximum amount of space that a user's Inbox can occupy. Like the maximum capacity of a floppy disk, it cannot be exceeded.

Soft Quotas

Soft quota is considered a reasonable limit for space that an Inbox should occupy. The size of a user's Inbox can exceed its soft quota, but only for a short period of time: the grace period. The difference between the soft and hard quotas is a sort of space loan, and the grace period is the term or payback time for that loan.

Grace Period

On engmail, the grace period is 14 days, so a user's Inbox may exceed its soft quota for up to 2 weeks at a time. The grace period "countdown" is reset when a user's Inbox is reduced in size to less than its soft quota.

Over Quota and Out of Time

When the hard quota is reached or the soft quota is exceeded and the grace period has expired, no additional space can be allocated for the user's Inbox. Mail is not delivered to the user. Newly arrived mail may wait for a few days in the hopes that it can be delivered but, if the Inbox is left full, eventually mail will be lost.

Quota Notification and Enforcement

Periodic notices help users manage the size of their Inboxes. The notices are automatically generated when a user's Inbox exceeds its soft quota, nears the end of its grace period, or the grace period expires.

In cases where the notices aren't sufficient (e.g. if mail in the Inbox is never read) an intermittent automatic process truncates the largest message in the Inbox. Eventually, the size of the Inbox is reduced to less than the soft quota, and normal mail delivery resumes.