Automatic junk mail filtering not working

Hey there MarionHF, 

Taking a look at If junk mail filters aren’t working in Mail on Mac   

"If junk mail isn’t highlighted to indicate it’s junk, check your junk mail preferences.

• Choose Mail > Preferences, then click Junk Mail. Make sure “Enable junk mail filtering” and “Mark as junk mail, but leave it in my Inbox” are selected.
• If you selected the junk mail option to exempt addresses in the Previous Recipients list from filtering, check that the list contains only valid addresses you want to receive messages from. See Remove obsolete email addresses.
• If the problem persists, click Reset in Junk Mail preferences to reset the junk mail database to its original information. Resetting the database removes everything Mail has learned from you about what is junk or not junk, so you need to help Mail identify junk mail again."

Have a good one!

Hi MarionHF,

If you'd like help with junk mail on Mac, these steps might help. 

- If Mail failed to mark the message as junk: Click the Junk button in the Mail toolbar (or use the Touch Bar). Mail moves the message to the Junk mailbox.

Each time you confirm a message as junk or not junk, the junk mail filter improves so Mail can better identify junk mail.

The information above is from Reduce junk mail in Mail on Mac. If the issue continues, let the community know if messages aren't moving to junk mail after you mark them. 

We hope that helps with your question and take care!