Know whose responder is acting
01A responder is software that sends mail after receiving mail. Personal, Service and Group Responders serve different purposes.
The guide concerns automatic-response behavior. DSNs and MDNs have separate governing specifications; an away notice is not a read receipt.
Source for this drawing: RFC 3834 · Read RFC section 1.1 ↗
New to this? Start hereA quick picture + helpful background
A message needs an address.
Think of a packet as a small addressed envelope. Devices pass it onward; transport protocols decide what delivery promises an application gets.
Helpful first, if these ideas are unfamiliar
These pictures are analogies to help you learn. The linked RFC explains the actual rules.
Terms in this drawing
Related RFCs and changes
“Updates” changes part of an earlier RFC. “Obsoletes” replaces it. This list shows selected related documents.
A Personal Responder acts for one recipient, such as a vacation reply. A Service Responder handles requests to a service address; its sender normally expects an automatic answer.
- A Personal Responder acts for one recipient, such as a vacation reply. A Service Responder handles requests to a service address; its sender normally expects an automatic answer.
- A Group Responder acts for many recipients under shared criteria, such as an organization-wide filter. The examples are alternatives, not successive hops of one conversation.
- Delivery Status Notifications report transport delivery; Message Disposition Notifications report disposition after mailbox delivery. Their own specifications govern their format and generation (section 3.2.1). A vacation reply proves neither delivery success nor human reading.
Fictional example.org addresses. Independent examples are labelled; this is guidance for responders, not a full mail parser or an authentication mechanism.
Read the RFC section ↗