by jbuk » Fri Oct 15, 2010 8:45 am
Yes, any message folder can be saved individually, you just need to specify the file name suffixes (.dat, .idb, .mbx) which are a subset of the folder you are saving, in whatever backup application you are using.
My current favorite is Cobian Backup as within this you can specify a differential backup which only saves the folders which have changed since the last full backup
This might not be what you are trying to achieve but does address your question.