Mbox to Maildir – Email storage file format systems

As there is no universal regulation or rule other than IMF (Internet Message Format) on how the emails are stored on the server – Mbox email storage file format system has been widely in use by the email clients developers for a long time. Mbox uses a single file where all of the information is stored in a single file having header information as well. As all of the information is stored in a single file, so there is a locking needed to prevent file corruptions and this proved to be a major deficiency of mbox. Other than this, some security flaws also have been discovered in mbox.

The author of the Qmail described Maildir, which uses /tmp location to store files temporarily for the emails thus having advantage & overriding the file lockings used in mbox.

cPanel officially announced support for Maildir in 2005[*]. And they provide a utility to convert mbox to maildir. Just run /scripts/convert2maildir and the menu like this would popup.

/scripts/convert2maildir
Mail Directory (maildir) Conversion System
maildir is not active, this system is using mbox

1) Backup all mail folders on this server
2) Restore a mail backup
3) Start maildir conversion process
4) Request Technical Support
*) Exit
Enter Selection—]

Backing up would be a good idea before running the conversion. For this, backup destination must have been described in WHM.