How do I create encrypted backups of gmail (or any other email) via IMAP client (e.g. Thunderbird)

Question

This question is regarding the use of Thunderbird (or other IMAP clients) and suggested backup and encryption tools, not Gmail.

I have Thunderbird setup to access an email account via IMAP (in this case the email account is gmail). I would like to create encrypted backups of the email, perhaps by year, e.g. 2005, 2006, etc.

What are some of the ways to accomplish this? What would work best and would be most accessible in the future? Are backups by year the best way to segment the data (if necessary?)

Although my main machine is Windows 7 64 bit, I see this as a "one-off" task, meaning I'll do it once a year or so and backup 12 months worth of email at a time. So I'm not limited in what hardware/software I use to do it, i.e. I can boot up OS X or Linux to accomplish this.

Answer 1

I don't know if you are still looking for a solution or not, but I would recommend a combination of a couple of technologies.

First I would use Thunderbird to download the messages. IMAP is great for day to day usage, but if you are just backing up to encrypt and store, I would use POP. Once your emails are downloaded and organized into the folders that you want (Thunderbird automatically separates archives into folders by year) you will be ready to encrypt.

To encrypt these files, take a look at TrueCrypt. It also is free, and will let you encrypt a group of files as one large, secure file.