SMTP server w/o using Twisted framework

[Gerhard Häring]

_spitFIRE wrote:
> [looking up DNS MX records]
> Thanks for the pointer. However, as I said currently, I can't use
> anything other than the standard libraries.

Sure you can. You just need to get rid of the "only standard library" 
requirement rule.

That works best by showing the alternatives to whoever set that requirement:

- use pyDNS
- use an existing (probably non-Python) SMTP daemon
- reimplement some parts of pyDNS yourself and develop a basic (crappy) 
SMTP daemon yourself

For doing the latter, you should budget at least one week.

FWIW another reason why SMTP servers should retry on temporary failure 
is that increasing use of Greylisting (*), which was precisely designed 
to filter out mail from "crappy" servers, like botnets, and - well - 
cheap custom written ones ;-)

-- Gerhard


(*) http://en.wikipedia.org/wiki/Greylisting - I use it myself