Short description of HS SMTP 2.0.0: HS SMTP is a software library in C (supplied with full source code) which implements the client side of Simple Mail Transfer Protocol (SMTP) over TCP socket layer according to RFC 821. Supports transfer of text and file attachments. HS SMTP Library incorporates the necessary state machine, transparency procedures, and server response processing required to comply to a simple and robust SMTP client implementation. Supports secure SMTP over TLS.