Reduce junk mail in Mail on Mac
You can mark messages as junk, adjust junk mail filter settings, block senders, unsubscribe from mailing lists, and set up automatic cleanup to reduce junk mail in your inbox.
Mark messages as junk or not junk
Tip: To minimize the amount of spam you might receive, make sure the junk mail filter is on. Choose Mail > Settings, click Junk Mail, then verify “Enable junk mail filtering” is selected.
Go to the Mail app
on your Mac.Select a message, then do one of the following:
Mark the message as junk: Click
in the Mail toolbar. Mail moves the message to the Junk mailbox.If Mail incorrectly marked the message as junk: Click Move to Inbox in the message banner or click
in the Mail toolbar. Mail moves the message to your Inbox.
Each time you confirm a message as junk or not junk, the junk mail filter improves so Mail can better identify junk mail.
Change junk mail filter settings
The default settings catch most of the junk mail you receive, but you can customize the filter.
Go to the Mail app
on your Mac.Choose Mail > Settings, then click Junk Mail.
Specify what Mail should do when junk mail arrives.
If you want to verify what the filter identifies as junk mail, select “Mark as junk mail, but leave it in my Inbox.”
If you’re sure the filter accurately identifies junk mail, select “Move it to the Junk mailbox.”
To set up other actions, select “Perform custom actions,” then click Advanced.
Note: To make sure the filter’s database is used to identify junk mail, don’t change the default condition “Message is junk mail.”
Select options for exempting messages from being evaluated, such as messages received from people who use your full name.
To include in the filter any junk mail detection inherent in messages, select “Trust junk mail headers in messages.”
Block or unblock senders
If you don’t want to receive email messages from a specific person or group, you can block them. If you change your mind later, you can easily unblock them.
Go to the Mail app
on your Mac.Select a message from the sender you want to block.
Move the pointer next to their name in the message header, click the arrow, then do one of the following:
Block a sender: Choose Block Sender.
The blocked icon
appears next to the sender’s name in the message list and a banner is added to the messages in the list to indicate they’re blocked.Unblock a sender: Choose Unblock Sender.
Tip: You can manage your blocked senders from the Blocked Contacts pane in Settings. Go to Settings 
> Privacy & Security > Blocked Contacts.
Unsubscribe from mailing lists
If you receive email messages from a mailing list, such as from a shopping website, you can easily unsubscribe from the list directly in Mail.
Go to the Mail app
on your Mac.Select a message you received from a mailing list.
A banner below the message header indicates if the message is from a mailing list.
In the banner, click Unsubscribe, then click OK in the alert that appears.
The banner disappears from the email as Mail unsubscribes you from the mailing list.
If you want to receive emails from the mailing list again, you must resubscribe directly with the sender.
Automatically clean up iCloud Mail
If you use iCloud Mail, you can automatically keep your inbox clean and free up storage by deleting old promotions, unsubscribing from mailing lists, and more with iCloud Mail Cleanup. See Clean up Mail automatically on iCloud.com.