Sending confidential e-mail using Apple Mail is always a risk if you don't use some kind of encryption. GPGMail gives you peace of mind as a secure plugin to encrypt e-mail send in Mail.
GPGMail is an open source plugin for Apple Mail which signs, verifies, encrypts and decrypts mails using something known as the PGP standard. Once installed, GPGMail encrypts your mail before sending it. GPGMail uses a special signature so that the receiver of the e-mail can be sure the information has been sent by only you. It's even possible for them to see if anything has been changed since the original was sent.
The only problem that Mail users may have with GPGMail however is with further updates to OS X. The last update to Snow Leopard caused many problems with Mail including the failure of GPGMail to work properly.
GPGMail gives Apple Mail users peace of mind that their mail is being sent securely.
