> On Jul 1, 2019, at 8:41 PM, Viktor Dukhovni <postfix-us...@dukhovni.org>
> wrote:
>
> The SMTP proxy can return 4XX if the HTTP POST fails. It can run
> as a threaded or forking server. In Python or Perl, I'd go with a
> forking server for simplicity. In Haskell, threading is very
> light-weight and safe/correct concurrency is pain-free, so if you
> need a lot more performance, Haskell (or Rust) would likely raise
> your throughput ceiling by an order of magnitude.
Python provides standard Lib/smtpd.py based on asynchronous socket handler.
This seems appropriate for a simple mail forwarding service that's just IO
bound.
