Emails from the same sender keep coming into my inbox even though I marked their previous emails as spam, why?
Missive does not perform any spam filtering on its own. When you click Mark as Spam in the interface, it does move the email to your Spam (or Junk) folder, but then it’s up to your email provider to learn from these actions. Unfortunately, generic IMAP servers tend to have much less intelligent spam filtering than big players such as Gmail / Google Workspace / Office 365, so it’s possible that emails from a sender you marked as spam still keep coming in your Inbox.
Missive solution
To automatically mark emails coming from certain email addresses as spam, you can implement this rule logic:
1. Add the email address to a contact group called Spam.

2. Create a rule that automatically marks all emails from email addresses in the contact group Spam as Spam.
