For “follow-up” module, messages get spam filtered in Apple’s mail client.
I spent some time figuring out what causes the spam flag. It turns out that it’s the unsubscribe link generated in the follow-up e-mails. There doesn’t appear to be a way to edit that though. Any suggestions?
(I did try it with the new option to avoid spam filters too, btw. No matter what else, it’s always the unsubscribe link that triggers Apple’s spam filter).