Quota
There are different quota backends that Dovecot can use:
- [wiki:Quota/FS fs]: Filesystem quota.
- [wiki:Quota/Dirsize dirsize]: The simplest, but sometimes slow, quota backend. It scans all the files from mail directories to calculate the quota.
- [wiki:Quota/Dict dict]: Store quota in a dictionary (table).
- [wiki:Quota/Maildir maildir]: Maildir++ quota.
There are currently two quota related plugins:
- quota: Implements the actual quota handling and includes also all the quota backends.
- imap_quota: For reporting quota information via IMAP.
Usually you'd enable these by adding them to the mail_plugins settings in the config file:
protocol imap { mail_plugins = quota imap_quota } protocol pop3 { mail_plugins = quota } # In case you're using deliver: protocol lda { mail_plugins = quota }
Most of the quota backends have a few things in common:
You can set the quota as kilobytes (called storage) and/or as number of messages (called messages). Usually only the storage quota is used. These limits can be given to the quota backend as parameters, e.g.:
plugin { # 10 MB quota limit quota = maildir:storage=10240 # 1000 messages quota limit quota = maildir:messages=1000 # 10 MB + 1000 messages quota limit quota = maildir:storage=10240:messages=1000 }
The above example shows how to set the same quota globally for everyone. You can override this for one or all users by returning a quota [:UserDatabase/ExtraFields:extra field] from the user database (in the exact same format as above). See UserDatabase for more information about how to set them for the user database you are using.
Examples
SQL
# MySQL: user_query = SELECT home, uid, gid, concat('maildir:storage=', quota_kb) AS quota FROM users WHERE userid = '%u' # PostgreSQL, SQLite: user_query = SELECT home, uid, gid, 'maildir:storage=' || quota_kb AS quota FROM users WHERE userid = '%u'
LDAP
# quotaStorage must be in the format mentioned above # For example: maildir:storage=10240 user_attrs = homeDirectory=home,uidNumber=uid,gidNumber=gid,quotaStorage=quota # If you have the quota already as kilobytes in LDAP, there's a kludgy way to use it directly: user_attrs = homeDirectory=home,uidNumber=uid,gidNumber=gid,quotaStorage=quota=maildir:storage
If you have the quota stored as bytes, you'll need to use a [:PostLoginScripting:post-login scripting] trick to use them. Something like:
# quotaStorage contains the quota in bytes. It's exported into # $QUOTA_BYTES environment. user_attrs = homeDirectory=home,uidNumber=uid,gidNumber=gid,quotaStorage=quota_bytes
And make imap's mail_executable point to a script:
export QUOTA=maildir:storage=`expr $QUOTA_BYTES / 1024` exec /usr/local/libexec/dovecot/imap