The easiest way to enable spam filtering is to leave your Yahoo! Mail Plus account as-is, since by default it's set to "I don't want to receive any messages that Yahoo! SpamGuard thinks are spam." This way, you enjoy spam protection even when you're checking your messages remotely.

Click Options in the upper-right corner of your Mail page and select More Options. From the list on the left, click POP & Forwarding, then click Set up or edit POP & Forwarding. If you want to see all your messages when you POP, even ones Yahoo! SpamGuard thinks are spam, then click in the circle next to I want to receive all messages, including those that Yahoo! SpamGuard thinks are spam.

If you make this selection, there’s a way to better manage the POPed emails SpamGuard thinks are spam. You can add the word "Bulk" to the subject line of all these messages. Then you can set up a filter on your mail client that notices the word "Bulk" and automatically routes those messages into a specific folder.

To set up a filter like that in your client email, take a look at the application's Help pages.

To add the word "Bulk" to all messages coming from your Spam folder:

1. Click "Options" in the upper-right corner of your Mail page and select "More Options".
2. From the list on the left, click "POP & Forwarding", then click "Set up or edit POP & Forwarding".
3. Select "I want to receive all messages, even those that Yahoo! SpamGuard thinks are spam." Then in the indented line just below, put a check in the box beside "For messages that Yahoo! SpamGuard thinks are spam, add [Bulk] as a prefix to the subject."
4. Click "Save".