Re: [Exim] maildir Vs. mbox

On Fri, 22 Oct 1999, Richard G. Duvall wrote:

...
> Reading what somebody said on this list, it is easier on the system to
> store each message in a seperate file (maildir), because it doesn't have
> to be moving files around to temporary files, or eating up memory to open
> them. However, I was reading the pine notes in the pine distribution, and
> it said that mbox was better, because it doesn't have a bunch of files to
> thrash around.
...

Actually, the Pine distribution recommends mbx, not mbox. mbx is an
indexed form of mbox.

The basic problems with mbox:

- Each line of the mailbox needs to be read to determine where a message
starts. The speed of opening a mailbox is dependant on the size of the
box.

- Message starts are indicated by a "\nFrom ", which means that lines
beginning with "From" have to escaped by your MTA


MBX and Maildir avoid both of these. MBX uses an index to keep track of
where messages begin.

Both MBX and mbox format mailboxes require some type of compaction when
individual messages are deleted. Not an issue if you are just using POP
though.

If you want to use POP, I'd never, never use mbox. It take far too long
to open a mailbox. Beats the hell out of your IO system.

I wouldn't put together a mailbox system today that didn't support IMAP.
IMAP is nice, and it makes it easy to support web mail interfaces. Plus
Pine has excellent IMAP support.

Tom