Change per-user mailbox format (e.g. maildir, mdbox)

iRedMail uses maildir mailbox format by default, it's easy to backup, migrate and recover. As long as mailbox grows larger and larger, the performance will be slower due to too much disk I/O - caused by maildir format. Dovecot's own mailbox format mdbox has very good performance for large mailbox due to reduced disk I/O.

You may want to switch to other mailbox format for some reason. To help you switch easily, iRedMail-0.9.9 introduces 2 new SQL columns (for SQL backends) and LDAP attributes (for LDAP backends) to help you switch per-user mailbox format easily. All mailbox formats supported by Dovecot are supported in iRedMail.



With mdbox format, if mailbox index files are damaged or lost, mail messages will be lost. Because one of the main reasons for dbox's high performance is that it uses Dovecot's index files as the only storage for message flags and keywords, so the indexes don't have to be "synchronized". Dovecot trusts that they're always up-to-date (unless it sees that something is clearly broken).

Please read documents on Dovecot website to make sure you fully understand the pros and (most importantly) cons of the format you're going to use: Mailbox Formats.


SQL backends

You can switch to different mailbox format with SQL commands below. We use MySQL for example here.

USE vmail;
UPDATE mailbox SET mailboxformat='mdbox', mailboxfolder='mdbox' where username="";

LDAP backends

You need some LDAP management tool like phpLDAPadmin, Apache Directory Studio, or command line tool ldapvi (you can install it with yum or apt-get command directly) to update mail user's LDIF data.

mailboxFormat: mdbox
mailboxFolder: mdbox