(registered 2007-03-08, last updated 2020-02-14) Header field name: Errors-To Applicable protocol: mail Status: deprecated Author/Change controller: IETF Specification document(s): RFC 2076, section 3.5 Related information: Errors-To is mentioned in RFC 1035 3.3.7 and RFC 2076 3.5, but it was never formally standardized. Errors-To is used by some mailing lists to reflect their envelope-sender address in the message header, typically the same as the Return-Path. Use of this header field is considered harmful and is strongly discouraged. Especially it won't help for the "Sender ID" scheme specified in RFC 4406 (Historic).