The following types of messages are exempt from junk-mail filtering: This section contains three options, all designed to keep Mail from falsely identifying good email. The first two--'Sender of message is in my Contacts' and 'Sender of message is in my Previous Recipients'--assume that anyone you've chosen to communicate with is unlikely to be a spammer. The third, 'Message is addressed using my full name', exists because it's rare that spam is addressed in this way. This could help the urologist who prescribes the drugs we discussed earlier.
Trust junk mail headers in messages: As email works its way through the Internet's various servers, it can be identified as junk mail before it gets to you. This identifying information is planted in the message in areas that you can't normally see. When this option is enabled (as it is by default), you're telling Mail to trust that when a message has been marked as spam prior to you receiving it, it really is junk and should be treated as such.
Filter junk mail before applying rules: This option, which is off by default, gives junk mail filtering priority when your mail is filtered. As the name implies, the junk mail technology examines your incoming email first and deals with the results. Then your rules kick in. Because I have created some rules that help filter unwanted mail, I leave this option off.
Reset button: If you've failed to train Mail or done it so rarely that you get bizarre results, it may be time to start over and commit to doing it right the next time. You do this by clicking Reset at the bottom of the preference. This erases any training you've done and restores the junk mail feature to its default settings.
Normally I'd wrap this up with "And that's junk mail filtering under Mail." But because Mail can do only so much (and I really, really hate spam), I'm going to suggest that there are more things you can do. (As well as things you shouldn't do.)
Get a prefiltered account: With the right email account, you can unburden Mail (or any other email client) from dealing with junk mail. All the major free email services--Gmail, Yahoo, and iCloud--have some variety of server-side spam filtering in place. This means that the junk is weeded out and filed in a special folder before it reaches your inbox. Gmail has the best reputation for offering junk-free inboxes. AOL, perhaps the worst. I've seen reports of varying results from Yahoo and iCloud--some people see virtually no spam while others find these services wanting.
Gmail offers the additional advantage that you can redirect mail from other accounts (these must be POP accounts) through your Gmail account. When you do this, Gmail's spam filters kick in and clean your mail before it reaches you. To set up this option, visit your Gmail page via a Web browser, click the Settings button, select the Accounts tab, and click the Add a POP3 Mail Account You Own link. You'll be walked through the process of redirecting your account through Gmail.
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