From postfix-users  Tue May 26 22:37:58 2020
From: Chris Wedgwood <cw () f00f ! org>
Date: Tue, 26 May 2020 22:37:58 +0000
To: postfix-users
Subject: Re: Preferred/maintained greylisting options?
Message-Id: <20200526223758.GA9293 () aether ! stupidest ! org>
X-MARC-Message: https://marc.info/?l=postfix-users&m=159053272114287

> Contrary to someone else's experience related in this thread, I
> still see a significant amount of spam that greylisting blocks, and
> extremely few spammers retry and get through.

I concurn, as reported, I curently see greylisting reduce spam by a
factor of 4.

> I have only had one known case (i.e. someone said they were
> expecting an email that they didn't receive) in a very long time
> where a legitimate email was greylisted and the sending server did
> not retry, and that was recently from an outlook365 server.

Aliexpress is one perplexing offender I've had to deal with.

The send badly formed messages, retry aggressively for a few seconds
then never again so messages get lost.

I've not been able to reach anyone there.