Be wary.
I'm a mathematics grad student (and we all know mathematicians not computer scientists design encryption schemes

), and I can tell you right now that a asymmetric (and preferably public-key) encryption system is the only system that is anywhere near secure (PGP is okay). I would say it is very secure (if you use a big key > 2048 bits), however, it has a downfall too. By using PGP, you can certainly draw attention to yourself from the NSA for example, however, the NSA could care less about drug dealing. Nothing is really safe however, because the feds could simply force you to give over your private keys, and if you refuse (or say you lost them) find you in contempt. Also, PGP only works if the person you want to send to has a public key. Which is rare.
There is a million and one fucking ways for the feds to bust you. The best way to stay safe is to keep a LOW PROFILE by using a little known free email service (that the feds would not even know existed, let alone monitor), and receive unencrypted inbound emails. For outbound emails, simply use chained anonymous remailers through a proxy.
Same thing for our friends "encrypted disk". The feds will FORCE him to decrypt it.
Now lets talk about this new 'service'.
1) Foolishly, you use the same handle and password for this service as your hushmail and ziplip, thus granting this user access to your hush and ziplip account.
2) This user, who you don't know, is going to have full access to your emails. He claims you can 'just use PGP', however, although PGP is relatively simple to use for someone with a solid computer foundation, it can be difficult and time consuming for the novice. This works the same way as offering a money back guarantee.. It's all based on the fact that you will be too lazy to encrypt on your own.
You would be a fool to sign up for this service.
twitched