MANY Years of experience in this Industry has taught me that the Most "UNSTABLE" types of Files, across Numerous Different Manufacturers and Products are Email Files. Trying to Migrate (Often IMPORTANT) emails from one system to another as the Computer Industry advances too fast for its own good, OFTEN results in the LOSS of Data, and Duplicating the Contents of emails in different File Types, before Migrating, Compacting, or whatever, takes FAR TOO LONG. So I've learnt to LEAVE The Files ALONE and Try to keep Duplicates, when time permits. I'm a New User of Thunderbird (because my previous Microsoft Product was "losing" files) and today, for the First Time I was ask to allow Thunderbird to COMPACT its files. I worry that this will make the Files HARDER / SLOWER to Access, MORE LIKELY to be LOST, and LESS EASY to Migrate at some time in the future. My Computer has TONS of Unused Space, so I have no Personal Need to Recover the 230MB Thunderbird is telling me it will Free Up.

What is your recomendation - based Primarly on the RELIABILITY and SECURITY of my Data.