Mutual Internet
Practices Asssoc.

About Scope


Compatible Low-level Email
Authentication and Responsibility

This is a pre-working group effort to pursue SMTP envelope authentication techniques, covering Certified Server Validation (CSV) and Bounce Address Tag Validation (BATV).

Although this activity is not (yet) under the IETF, it is being conducted according to IETF rules and culture.

A draft charter for the working group is intended for discussion and refinement. It states the purpose and workplan of the proposed IETF effort; it therefore also defines the scope and effort of the mailing list.

Sometimes, Matthew's CLEAR Wiki is useful for adding and tracking modifications to the draft charter or other comments and suggestions.

An mailing list has been established and is open for subscriptions




Certified Server Validation (CSV) provides a mechanism for a mail-receiving server to assess a mail-sending server. In particular, CSV permits a mail-receiving server to determine:

    1. Whether a mail-sending relay host is correctly identifying itself
    2. Whether the operator of the sending host's network has authorized it to operate as a mail relay
    3. Whether independent parties have a good assessment of the quality of that network's mail operation; that is, whether they are less-likely or more-likely to be the source of problematic email.



Bounce Address Tag Validation (BATV) provides a mechanism for assessing the validity of an email's envelope return (bounce) address. It permits the original submitter of a message to sign the SMTP MailFrom address. This enables detection of invalid bounce addresses.

Comments concerning this site should be sent to: