How to configure ISPConfig 3 so that it accepts all email messages, and those marked as spam are moved to the Spam folder? With the default ISPConfig + rspamd settings, it can reject messages, e.g., to strava.com. What do you recommend doing?
You can configure the spam mark and rejection levels in the spam filter policies (or just select a policy that matches what you intend in the email mailbox or email domain settings). And to move spam to junk folder, there is a checkbox for that in the mailbox settings.