Impressive unicorn.
That's much more than what I expected from TheBat!.
However, strictly speaking my requirements still remain unsolved. Integration wasn't my #1. My #1 was the method of Email storage. The way TheBat! stores emails looks simlar to the way Thunderbird stores emails. I don't see an easy of way having 2004 Emails in folder/file and 2005 emails in another folder/file.
Speaking more about the way I organize PST files: I create a new PST file every year. For 5 years of Emails, I will simply have 5 PST files. I still prefer this email management over other methods that email clients have.
I highly value discussion about the use of different software that fulfills the same requirement. So Discussion about all Email Clients are welcome in this thread...
Cheers,
McoreD