Added
- [**Extension Consolidation**][15].
- New [`create_listeners`][10] function for creating IP sockets on both IPv4
and IPv6, if available.
- New `mixin` functions in the [`proxyproto`][12] classes.
- Support for `AUTH=` parameter to `MAIL FROM` command.
- Allow providing custom [`SmtpSession`][8] class to [`SmtpEdge`][9].
Changed
- [`WsgiEdge`][11] listener creation was made more consistent with other edges.
- [`StaticLmtpRelay`][13] now returns success (250) responses as well.
- Multi-recipient messages to [`pipe`][14] with `per_recipient` flag set will
execute once per recipient with partial delivery responses.
Fixed
- The result of the reverse IP lookup was never consumed in [`SmtpEdge`][9].
- Fix various issues in the [`proxyproto`][12] implementations.
- Corrected sorting of AUTH mechanisms.
- Fix SMTP client always choosing `PLAIN` AUTH mechanism even if it is not
advertised, instead of best available.