Hello
On 2004-07-20 Russell Coker wrote:
(host mail3av.westend.com[212.117.79.67] said: 450 <ch@lathspell.de>:
Recipient address rejected: Greylisted for 300 seconds... (in reply to
> RCPT TO command)) ch@lathspell.de
Christian's mail server is broken.
Err, no. It's not a bug it's a feature :-) Called "greylisting".
In opposide to normal black- and white-listing here postfix has an
additional policy daemon that checks if the tripel "sending ip, from,
to" is already in the database and if not, reply with a 450 aka
"temporary(!) failure" code and take note of it. If it's a real
mailserver and not a trojan-winXP-desktop then it will try it again in a
couple of minutes. If it does the above tripel will be whitelisted for
the next days/month/whatever.