RFC 5321 says: "As discussed in Section 7.8 and Section 7.9 below, dropping mail without notification of the sender is permitted in practice." http://tools.ie

RFC 5321 says: "As discussed in Section 7.8 and Section 7.9 below, dropping mail without notification of the sender is permitted in practice." http://tools.ietf.org/html/rfc5321#section-6.2 http://tools.ietf.org/html/rfc5321#section-6.2