An ESMTP client and server library written in Go.

• ESMTP client & server implementing RFC 5321
• Support for additional SMTP extensions such as AUTH and PIPELINING
• UTF-8 support for subject and message
• LMTP support

The Go standard library provides a SMTP client implementation in net/smtp. However net/smtp is frozen: it's not getting any new features. go-smtp provides a server implementation and a number of client improvements.

MIT