NeoCertified Secure Email - NeoCertified is a solution that provides secure email encryption for businesses and organizations across all industries, including healthcare, finance, legal, non-profit and education.

TheLetterEncrypter - TheLetterEncrypter is a small (14KB download) AES-based text-encryption program.

Virtru - Virtru is your data privacy force field, wrapping and protecting emails and files wherever they're shared. Easy-to-use data security software for business. People also askIs Virtru Hipaa compliant?

GNUPGK - A GnuPG Frontend GUI made in C#.

Proofpoint Email Encryption - As email is the preferred medium for business communications, preventing confidential information from being leaked in outbound email messages must be a top priority in order to lower the risk of a data breach.

CTI Text Encryption - CTI Text Encryption is an encryption tool that can encrypt any text from messages and articles to codes, etc.