quota update

Configure-Accounts.md

@@ -22,4 +22,36 @@ You will be asked for a password. Just copy all the output string in the file `c
 The `doveadm pw` command let you choose between several encryption schemes for the password.
 Use doveadm pw -l to get a list of the currently supported encryption schemes.
 
-> Note: changes made with this script require a restart of the container. See [#552](../issues/552)
+> Note: changes made with this script require a restart of the container. See [#552](../issues/552)
+
+***
+## Mailbox quota
+**coming soon: https://github.com/tomav/docker-mailserver/pull/1469**
+
+On top of the default quota (`POSTFIX_MAILBOX_SIZE_LIMIT`), you can define specific quotas per mailbox.
+Quota implementation relies on [dovecot quota](https://wiki.dovecot.org/Quota/Configuration) which requires dovecot to be enabled. Consequently, quota directives are disabled when `SMTP_ONLY` is enabled.
+<br>
+
+
+A warning message will be sent to the user when his mailbox is reaching quota limit. Have a look at [90-quota.cf](https://github.com/tomav/docker-mailserver/tree/master/target/dovecot/90-quota.conf) for further details.
+
+### Commands
+_exec in the container_
+
+- `setquota <user@domain.tld> [<quota>]`: define the quota of a mailbox (quota format e.g. 302M (B (byte), k (kilobyte), M (megabyte), G (gigabyte) or T (terabyte)))
+- `delquota <user@domain.tld>`: delete the quota of a mailbox
+- `doveadm quota get -u <user@domain>`: display the quota and the statistics of a mailbox
+
+### `dovecot-quotas.cf`
+
+This file is a key-value database where quotas are stored.
+
+_dovecot-quotas.cf_
+```
+user@domain.tld:50M
+john@other-domain.tld:1G
+```
+### Notes
+- *imap-quota* is enabled and allow clients to query their mailbox usage.
+- When the mailbox is deleted, the quota directive is deleted as well.
+- LDAP ? Dovecot quotas supports LDAP **but it's not implemented** (_PR are welcome!_).