When comparing Tox vs Email + PGP, the Slant community recommends Email + PGP for most people. In the question“What are the best ways to transmit sensitive information over the Internet?” Email + PGP is ranked 2nd while Tox is ranked 10th. The most important reason people chose Email + PGP is:
The original version of PGP is no longer freeware since it was aquired by Symantec, but the source code can still be [downloaded](http://www.symantec.com/connect/downloads/symantec-pgp-desktop-peer-review-source-code) for peer review.
Ranked in these QuestionsQuestion Ranking
Pro Free and open source
The code is licensed under GPL (may change in the future) and is available on GitHub.
Pro Multiple front-ends for multiple platforms available
At the moment there is no official Tox client, but a selection of 32 and 64 clients for Windows, OS X, Linux and Android is available.
Pro Privacy focused
Tox uses military grade encryption and works completely peer-to-peer.
Pro Code available for audit
The original version of PGP is no longer freeware since it was aquired by Symantec, but the source code can still be downloaded for peer review.
Pro No need to exchange private keys
PGP uses asymmetric encryption. One user generates 2 keys - private and public. Another user uses the public key to encrypt the message that can then be decrypted only using first users's private key.
Pro Can be integrated with multiple email clients
Pro Many implementations available
PGP is a protocol and not an application per se. It offers a standard on which applications can implement to offer full encryption.
Con Early stages of development
Since Tox is relatively new, it has important features missing (like group video) and requires a proper code review before it can be deemed reliable and ready for everyday use.
Con Can be daunting to set up
If your email client doesn't support PGP encryption, decrypting e-mails ca be dauting, especially if you want to stay away from command line.