I signed up for a new project with MailChimp... every time it sends the account activation email rspamd greylists them. I have added @mailchimp.com and @mandrillapp.com to the postfix whitelist as sender, and I've added both domains to spamfilter whitelist for my domain, but it gets greylisted and Mailchimp doesn't seem to resend later. What can I do to prevent these soft-errors? ISPConfig 3.2.11p2
Thats the wrong spot to whitelist. Remove that entry. As for the spamfilter whitelist what options did you set there? Are you sure about that? Any sane mailserver recognizes and respects greylisting. Be aware that greylisiting times vary from setup to setup so it is quiet possible that mailchimp resends this mail after 10, 15, 20 or even 30 minutes - allthough 10 minutes is the norm here.
Yes, I'm sure. I started this yesterday, repeatedly asked to have the activation resent, and rspamd just greylist's them everytime. This is how I set up the whitelist under Spamfilter > WhiteList. The mandrillapp.com is there "just in case" but this hasn't worked either.