1 Introduction

The Simple Mail Transfer Protocol (SMTP) AUTH LOGIN Extension is an authentication mechanism that provides an easily implemented method for clients to authenticate to SMTP servers over a standard SMTP connection. This extension uses the SMTP Service Extension for Authentication, as specified in [RFC4954], to extend SMTP.

Sections 1.5, 1.8, 1.9, 2, and 3 of this specification are normative. All other sections and examples in this specification are informative.