该软件和mpop是姊妹软件，这是一款专门负责邮件发送的客户端软件，基于GPL发布。支持TLS/SSL、DNS模式、IPv6、服务器端认证、多用户等特性。-msmtp is an SMTP client with a sendmail compatible interface. It can be used with Mutt and other mail user agents.

nPOPuk v3.04 source Email SMTP IMAP 4.0 POP 3.0 Encrypted, SSL, TLS, Mail Transfer Agent, MTA