3.12.4 Mailbox Quotas

Mailbox quota is a limit on the size of the mailbox. When a mailbox size reaches this limit, mda stops accepting messages for this recipient and returns an error condition to the sender. The error code is accompanied by the following error message:

user: mailbox quota exceeded for this recipient

Furthermore, if accepting the incoming message would make the mailbox size exceed the quota, such a message will be rejected as well. In this case, the error message is:

user: message would exceed maximum mailbox size for this recipient

In both cases, the default return code will be ‘service unavailable’ (corresponding to the SMTP return code ‘550’), unless the following statement is present in the maidag configuration file:

quota {
  exit-tempfail yes;
}

in which case a temporary error will be returned.

The mailbox quota can be retrieved from the following sources:

1. Authentication method.
2. DBM file.
3. SQL database.