Master password in Firefox or Thunderbird? Do not bother

There is a weakness common to any software letting you protect a piece of data with a password: how does that password translate into an encryption key? If that conversion is a fast one, then you better don’t expect the encryption to hold. Somebody who gets hold of that encrypted data will try to guess the password you used to protect it.

And modern hardware is very good at validating guesses.

Source: palant.de