RSET
RSET is a command used in the Simple Mail Transfer Protocol (SMTP) to reset the current mail transaction without closing the network connection. It is defined in RFC 5321, the standard specification for SMTP, and has historically appeared in earlier RFCs as well. The command is client-initiated and is intended to abort a partially formed message so that a new mail transaction can begin.
When a client issues RSET, the server discards any envelope state associated with the current transaction.
RSET is commonly used when an error is encountered during message composition or during command processing,
See also: SMTP command set (HELO/EHLO, MAIL FROM, RCPT TO, DATA, QUIT), RFC 5321, and related SMTP