Q: How do I make my third-party auto-responder well-behaved?

I'm using a third-party auto-responder. What rules should I use to make it be well-behaved (i.e. to avoid sending inappropriate auto-responses - for example to mailing lists)?

Answer

Here are some suggestions:

1. When you send auto-responses, send them to the address in the RFC 821 "MAIL FROM" command. This address is often presented in a "Return-Path" header. If this address is null (often shown as "Return-Path: <>") then don't send an auto-response.
2. Don't send an auto-response if the recipient's email address does not appear in either the "To:" or "Cc:" header.
3. Don't send an auto-response if the message contains one of the following "Precedence:" headers:
   • Precedence: bulk
   • Precedence: junk
   • Precedence: list
4. Don't send an auto-response if the message contains an "Auto-Submitted:" header.
5. Don't send an auto-response if the message contains an "X-Mailer: vacation" header.
6. Don't send an auto-response if the recipient's email address appears in the "From:" header.
7. Don't send an auto-response if either the RFC 821 "MAIL FROM" command (often presented in a "Return-Path" header) or the "From:" header contains one of the following addresses:
   • LISTSERV@[any host]
   • MAILER-DAEMON@[any host]
   • MAJORDOMO@[any host]
   • [any string]-REQUEST@[any host]
   • OWNER-[any string]@[any host]