[Mailman-Users] Mailman Hosting

Richard Shetron guest2 at sgeinc.com
Fri Dec 23 14:17:46 EST 2016

Postfix is the same.  I had to install a greylisting package to add 
greylisting to postfix.

On 12/23/2016 9:50 AM, Odhiambo Washington wrote:
> On 23 December 2016 at 17:36, Richard Shetron <guest2 at sgeinc.com
> <mailto:guest2 at sgeinc.com>> wrote:
>     Maybe they were using some type of grey listing.
>     For those who don't know:
>     Grey listing is where the target MTA rejects with a retry error code
>     the email from a new source for some period of time.  Every site can
>     set their own delay.  Most spammers won't retry so it gets rid of a
>     lot of spam.  Real email servers will accept the retry error (4xx)
>     and retry after some prefigured time from a few seconds to an hour
>     or more.  The IP addresses are tracked and if retried after the time
>     limit are white listed for anywhere from a few hours to a month or more.
> I know Exim will only treat a session as a failure if it gets 5xx. Does
> Postfix do the same?
> --
> Best regards,
> Odhiambo WASHINGTON,
> Nairobi,KE
> +254 7 3200 0004/+254 7 2274 3223
> "Oh, the cruft."

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