3.10.3 Setting up Mailbox Quotas

Sometimes it is necessary to limit the maximum size of a user's mailbox. Such maximum size is called mailbox quota for this user.

When delivering a message, mail.local first cheks if the mailbox quota is specified for the recipient. If so, mail.local computes the difference between the quota value and the actual size of the recipient's mailbox. This difference represents the maximum size of the message the receipient's mailbox is able to accomodate. Let's call it msize. Depending on its value, mail.local takes decision on whether to deliver the message. There are three possible cases:

1. msize equals zero. This means that the mailbox size has reached its limit). In this case the message is not delivered and the sender receives following notification message:

   user: mailbox quota exceeded for this recipient

2. msize is less than the size of the message mail.local is about to deliver. In this case the message is not delivered and the sender receives following notification message:

   user: message would exceed maximum mailbox size for this recipient

3. msize is greater than or equal to the size of the message. In this case mail.local does deliver the message.

Version 0.6 of GNU mailutils is able to retrieve mailbox quotas from a DBM or SQL database.

3.10.3.1 Keeping Quotas in DBM Database
3.10.3.2 Keeping Quotas in SQL Database