I find it hard to understand all the one star ratings for this program. While FastMailBase may not have the flashiest graphics, it does a very good job at archiving your mail - and allowing you to quickly and reliably find mail items afterwards.

I like the fact that you can have it archive messages on startup, as well as deleting the message from Mail after archiving. I also like the MIME message handling and ability to show graphical attachments. It is always easy to see which messages have attachments and to view them. Searching on various parameters is easy to do and very fast to complete.

Downsides are that it keeps claiming a newer version exists (it doesn't), and the price - which is on the high side. It can take a little while to import messages, but let it churn away and it will complete (I imported around 1,000 messages from Mail without any issues).

I recommend taking a look at the program and checking out its functionality. It really offers all that you could reasonably look for, and offers a good way to stop Mail choking on old messages and their attachments.