Crash and hence DB upgrade for version 2.1.18

[imap at adari.net]

Hello,

We have an old version (2.1.10?) running on one of our servers
which crashed today. We are still trying to access the server
so that we can determine what is the amount of data loss we
have. In the mean time, I thinking of building another machine
maintaining pretty much the same versions (but going with the
most latest bug fixed version at that level). However, I am
thinking of using the db-4.3.x, where as the old setup may have
used 4.0.x.

Assuming that we are able to get our hands on the mailboxes, can
simply copy over the files on a similarly named partitions and 
start the cyrus-imap 2.1.18 (built with 4.3.x)? 

Thanks