MacLife 101: How to Filter Spam in Apple Mail

The Mac|Life 101 series is where you can come to learn new and simple ways to do things with Apple’s desktop and mobile operating systems. Whether you’re new to the platform, or just want to learn a new technique, then Mac 101 is for you.

Spam is everywhere, but with modern email, you can smartly combat this problem. Built into every Mac is the ability to filter out the spam from your Inbox. Apple has made this a relatively simple process with the Mail application, but we’ll show you the ropes in this how-to. Continue reading to learn all about spam filtering on the Mac.

To enable the Mail spam filter, navigate to Mail > Preferences > Junk Mail. Once there, check the box labeled “Enable junk mail filtering.” As a safeguard, ensure that the option to “Mark as junk mail, but leave it in my Inbox” is selected under the “When junk mail arrives” option.


In the second section of the Junk Mail preferences, you have the ability to select which types of messages are automatically exempt from junk mail filtering. You can select “Sender of messages is in my Contacts,” “Sender of message is in my Previous Recipients,” or “Message is addressed using my full name.” With any of these options checked, the messages that match the rules will never be marked as spam, and thusly not removed from Mail.

The next to last option, “Trust junk mail headers in messages” gives Mail the ability to see the junk mail message headers set by your Internet Service Provider (ISP) or email provider. Checking this option will help Mail more accurately mark spam messages.

The last option, “Filter junk mail before applying my rules” lets Mail first filter your mail before using your rules to make changes to the messages. For more information about how to set rules, check out our previous post.

If a message matches the junk mail criteria, then a bar will appear near the top of the message. External images in the message will automatically be disabled, so that spam authors won’t be able to track if you’ve opened the message. To load the images, click the “Load Images” button in the bar, or to mark the message as not junk, select “Not Junk.”

Training the junk mail filter is imperative to getting good spam filtering results. To train your filter, you’ll want to mark all of the spam messages coming into your Inbox as such by first selecting the message, and clicking Message > Mark > As Junk Mail; you can also select the message and press Shift + Command + J.

If a message comes in that isn’t junk, be sure to let Mail know, by pressing the “Not Junk” button in the spam label bar in the message.

After a while, the junk mail filter will begin correctly identifying spammy messages. Once you feel comfortable with the results, go back to preferences and select “Move it to the Junk mailbox” for the “When junk mail arrives” option. This will automatically move spammy messages to the “Junk” folder in Mail’s sidebar. You’ll want to periodically go to that folder to check out the message to make sure that Mail is correctly identifying the junk mail, and not marking legitimate mail as junk.

Cory Bohon is a freelance technology writer, indie Mac and iOS developer, and amateur photographer. Follow Cory Bohon on Twitter.