Description:
URL for mailing list unsubscription

Applicable protocol: Mail [18]

Status: standards-track

Author/change controller:
IETF  (mailto:iesg&ietf.org)
Internet Engineering Task Force

Specification document(s):
RFC 2369 [13]

Related information:
Contains the URL to use to unsubscribe the mailing list from which
this message was relayed.

IANA Note:
According to Web principles (per http://www.w3.org/TR/webarch/#safe-
interaction), an HTTP GET request to the "List-Unsubscribe" URL should
not change the subscription state without some further interaction
involving something other than a "safe" HTTP interaction; e.g., a form
response that performs an HTTP POST operation when a user confirms that
they should be unsubscribed. In practice, many mailers do in fact
complete the unsubscribe operation on receiving an HTTP GET to this URL,
which can cause problems (e.g. when the URL is retrieved by a mail
content scanner). The "List-Unsubscribe-Post" header provides a way to
access the "List-Unsubscribe" URL with more predictable semantics.