On Tue, 2022-09-20 at 20:16 +0930, Tim via users wrote:
> On Mon, 2022-09-19 at 21:59 -0500, Chris Adams wrote:
> > Mail servers, on the other hand, were jumping to the file-per-
> > message
> > method just as fast as Usenet servers discarded it, and are still
> > using
> > it.
>
> I certainly noticed a massive improvement when I went from mail spool
> files to maildir on Dovecot.

Indeed. The old mbox format has a number of disadvantages. Expunging
deleted messages can mean copying a large file, which is a) slow and b)
may not succeed if the user doesn't have enough space. This would tend
to happen precisely when the user noticed his quota running out and
wanted to expunge deleted files to recover space. Oh, the irony :-)

They also require a locking mechanism, which could be problematic with
NFS-mounted mailboxes. Maildir largely eliminates these issues.