[Dovecot] New mailbox format

[Cor Bosman]

> It mostly has to do with the filesystem being used.  The System V based
> extended filesystems (which most people know as "ext2" and "ext3") have the
> same history as the BSD filesystem ("ufs" or "ffs"), and neither is
> particularly efficient at handling a directory of more than 10k files or so.

ufs on FreeBSD is hashed. "options  UFS_DIRHASH"

Just get a NetApp and be done with it :)

Cor