PGP Tool is described as 'has following features:'. There are four alternatives to PGP Tool for a variety of platforms, including Mac, Windows, Microsoft Office Outlook, S/MIME and Apple Mail. The best alternative is GPG4Win, which is both free and Open Source. Other great apps like PGP Tool are GPGTools (Freemium, Open Source), PGP Tool (Free, Open Source) and Pignus Encryption (Paid).
Gpg4win enables users to securely transport emails and files with the help of encryption and digital signatures. Encryption protects the contents against an unwanted party reading it. Digital signatures make sure that it was not modified and comes from a specific sender.