compare. Unfortunately I don't have a test system available to do all the mailbox types. I can only test mbox on my production system. That
When you rebuild your server, switch to some kind of virtualisation option! Never again will you not have a test architecture or any issue in spinning out a quick system to "try something out". With so many quite simple to use options available these days there is really near zero reason not to use virtualisation on your next server?
Just to put a stake in the ground - I have had very good success with linux-vservers. These are effectively a kind of chroot on steroids and similar to lxc containers, etc. This type of "virtualisation" is very lightweight (and not really a proper virtualisation to be fair) and it's extremely straightforward to migrate machines between real hardware, copy a machine for testing, backup, etc (takes around 1-3 mins to duplicate most of my virtualised machines - some might argue that's slow, but it's good enough for me)
I'm sure there are a bunch of reasons you can't use this today, but hopefully something to plan ahead for?
Good luck
Ed W