[Dovecot] mdbox, mdbox_rotate_size 2m default

[Timo Sirainen]

On Sat, 2010-07-17 at 23:25 -0700, Brandon Lamb wrote:
> Anyone else test using different values?
> Was 2M chosen as a default based on anything specific?

Because UW-IMAP's mix format uses 2 MB. IIRC Mark also didn't have
anything but his gut feeling when choosing the 2 MB..

> Is there any kind of known range where performance starts to go
> downhill if its greater than x or less than y?

Nope.