Introduction

This library provides an asyncio based implementation of a server for RFC 5321 - Simple Mail Transfer Protocol (SMTP) and RFC 2033 - Local Mail Transfer Protocol (LMTP). It is derived from Python 3’s smtpd.py standard library module, and provides both a command line interface and an API for use in testing applications that send email.

Inspiration for this library comes from several other packages:

aiosmtpd takes the best of these and consolidates them in one place.

Relevant RFCs

  • RFC 5321 - Simple Mail Transfer Protocol (SMTP)
  • RFC 2033 - Local Mail Transfer Protocol (LMTP)
  • RFC 2034 - SMTP Service Extension for Returning Enhanced Error Codes
  • RFC 6531 - SMTP Extension for Internationalized Email