Free
Free
http://free.antivirus.com/email-encryption-service
Mcafee
Mcafee saas email encryption is a cloud-based solution that saves you time and money by eliminating ongoing email management and maintenance.
http://www.mcafee.com/us/products/saas-email-encryption.aspx
Proofpoint
Email encryption: proofpoint encryption offers powerful, policy-driven encryption features that mitigate the risks associated with regulatory violations, data loss and corporate policy violations, without adversely impacting business operations.
http://www.proofpoint.com/products/privacy/email-encryption.php
Security
Security
http://www.security.nl/artikel/31276/1/%22Alleen_Google_kan_e-mail_encryptie_succes_maken%22.html
Trendmicro
Email encryption solution that fits your gateway -based encryption, client user-driven email encryption, and even a secure email hosted solution.
http://www.trendmicro.com/us/enterprise/network-web-messaging-security/email-encryption/index.html
Symantec
Pgp® desktop email from symantec is email encryption software that offers automatic email encryption, without affecting the end-user experience. learn about this secure email solution.
http://www.symantec.com/business/desktop-email
Voltage SecureMail
Voltage SecureMail
http://www.voltage.com/products/securemail.htm