Send, receive, edit, sign/verify and encrypt/decrypt email messages in any .NET application or service. 

Integrated Security

Level 1

  • Servers usually require client authentication. PowerTCP supports all typical techniques, including GSSAPI and NTLM (that can be used in single-sign-on mode where the current user's credentials are used).
  • A username and password is required in all cases except single-sign-on.

Level 2

  • Secure Socket Layer (SSL) ensures link-level privacy.
  • SSL can be implicit, where a dedicated server port expects an immediate SSL negotiation upon connection establishment, or explict, where SSL is negotiated on demand. PowerTCP supports both techniques using simple configuration properties.
  • SSL 2.0, SSL 3.0, PCT, TLS 1.0, 1.1, 1.2 is supported.

Level 3

  • S/MIME version 3.2 standards (backwards compatible to version 3.0) enforce message authentication and message privacy:
  • Message authentication is implemented by the sender performing a one-way hash on the message and his public key. The receiver duplicates this hash (using the sender's public key in the included X509 certificate), and a matching hash verifies the message is intact and was sent by the individual identified in the X509 certificate.
  • Message privacy is implemented by the sender encrypting the message using the recipients public key. Only the recipient can decrypt this message because only he has the necessary private key.
  • Typically, user1 will send a signed message to User2. User2 now has user1's public key. User2 can use that public key to encrypt a response to User1, and then User2 can also "sign" the encrypted message so that User1 gets his public key. From that point onward both users can send the other encrypted, signed messages.
  • MailMessage methods SecureSign(), SecureEncrypt() and SecureDecode() perform these functions.

X509 certificate management is automatic when possible, but included sample source code (VB and C#) is useful when user interaction is required.