Microsoft Windows Vista Unveiled

Thwarting Spam with Windows Mail's Junk Filter

Spamunsolicited commercial messageshas become a plague upon the earth. Unless you've done a masterful job at keeping your address secret, you probably receive at least a few spam emails every day, and it's more likely that you receive a few dozen. The bad news is that most experts agree that it's only going to get worse. And why not? Spam is one of the few advertising media for which the costs are substantially borne by the users, not the advertisers.

The best way to avoid spam is to not get on a spammer's list of addresses in the first place. That's hard to do these days, but there are some steps you can take:

• Never use your actual email address in a newsgroup account. The most common method that spammers use to gather addresses is to harvest them from newsgroup posts. One common tactic you can use is to alter your email address by adding text that invalidates the address but is still obvious for other people to figure out:

  user@myisp.remove_this_to_email_me.com

• When you sign up for something online, use a fake address, if possible. If you need or want to receive email from the company and so must use your real address, make sure you deactivate any options that ask if you want to receive promotional offers. Alternatively, enter the address from an easily disposable free web-based account (such as a Hotmail account) so that any spam you receive will go there instead of to your main address. If your free email account gets too overrun with junk mail, remove it and create a new one. (You can also do this through your ISP if it allows you to create multiple email accounts.)

• Never open suspected spam messages because doing so can sometimes notify the spammer that you've opened the message, thus confirming that your address is legit. For the same reason, you should never display a spam message in the Windows Mail Preview pane. Shut off the Reading pane (select View, Layout, deactivate Show Preview Pane, and click OK) before selecting any spam messages that you want to delete.

• NeverI repeat, neverrespond to spam, even to an address within the spam that claims to be a "removal" address. By responding to the spam, all you're doing is proving that your address is legitimate, so you'll just end up getting more spam.

If you do get spam despite these precautions, the good news is that Windows Mail comes with a Junk Email feature that can help you cope. Junk Email is a spam filter, which means that it examines each incoming message and applies sophisticated tests to determine whether the message is spam. If the tests determine that the message is probably spam, the email is exiled to a separate Junk E-mail folder. The Windows Mail spam filter is based on the much-admired filter that comes with Outlook 2003, which was voted best spam filter by Consumer Reports in September 2005. It's not perfect (no spam filter is), but with a bit of fine-tuning as described in the next few sections, it can be a very useful antispam weapon.

Setting the Junk Email Protection Level

Filtering spam is always a trade-off between protection and convenience. That is, the stronger the protection you use, the less convenient the filter becomes, and vice versa. This inverse relationship is caused by a filter phenomenon called the false positive. This is a legitimate message that the filter has pegged as spam and so (in Windows Mail's case) moved the message to the Junk E-mail folder. The stronger the protection level, the more likely it is that false positives will occur, so the more time you must spend checking the Junk E-mail folder for legitimate messages that need to be rescued. Fortunately, Windows Mail gives you several Junk Email levels to choose from so you can choose a level that gives the blend of protection and convenience that suits you.

To set the Junk Email level, select Tools, Junk E-mail Options. Windows Mail displays the Junk E-mail Options dialog box. The Options tab, shown in Figure 6.25, gives you four options for the Junk Email protection level:

• No Automatic Filtering This option turns off the Junk Email filter. However, Windows Mail still moves messages from blocked senders to the Junk E-mail folder (see "Blocking Senders," later in this chapter.) Choose this option only if you use a third-party spam filter or if you handle spam using your own message rules.

• Low This is the default protection level, and it's designed to move only messages with obvious spam content to the Junk E-mail folder. This is a good level to start withparticularly if you get only a few spams a daybecause it catches most spam and has only a minimal risk of false positives.

• High This level handles spam aggressively and so only rarely misses a junk message. On the downside, the High level also catches the occasional legitimate message in its nets, so you need to check the Junk E-mail folder regularly to look for false positives. Use this level if you get a lot of spama few dozen messages or more each day.

  Note

  If you get a false positive in your Junk E-mail folder, click the message and then select Message, Junk E-mail, Mark as Not Junk.

• Safe Lists Only This level treats all incoming messages as spam, except for those messages that come from people or domains in your Safe Senders list (see "Specifying Safe Senders," later in this chapter) or that are sent to addresses in your Safe Recipients list. Use this level if your spam problem is out of control (a hundred or more spams each day) and if most of your nonspam email comes from people you know or from mailing lists you subscribe to.

If you hate spam so much that you never want to even see it, much less deal with it, activate the Permanently Delete Suspected Junk E-mail check box.

Caution

Spam is so hair-pullingly frustrating that you might be tempted to activate the Permanently Delete Suspected Junk E-mail check box out of sheer spite. I don't recommend this, however. The danger of false positives is just too great, even with the Low level, and it's not worth missing a crucial message.

Fine-Tuning the Spam Filter

You can improve the performance of the Junk Email filter by giving Windows Mail a bit more information. Specifically, you can specify safe senders and you can block senders and countries.

Specifying Safe Senders

If you use the Low or High Junk Email protection level, you can reduce the number of false positives by letting Windows Mail know about the people or institutions that regularly send you mail. By designating these addresses as Safe Senders, you tell Windows Mail to automatically leave their incoming messages in your Inbox and never to redirect them to the Junk E-mail folder. And certainly if you use the Safe Lists Only protection level, you must specify some Safe Senders because Windows Mail treats everyone else as a spammer (unless someone sends mail to an address in your Safe Recipients listsee the next section).

Your Safe Senders list can consist of three types of addresses:

• Individual email addresses of the form someone@somewhere.com. All messages from these individual addresses will not be treated as spam.

• Domain names of the form @somewhere.com. All messages from any address within that domain will not be treated as spam.

• Your Contacts list. You can tell Windows Mail to treat everyone in your Contacts list as a Safe Sender, which makes sense because you're unlikely to be spammed by someone you know.

You can specify a Safe Sender either by entering the address by hand (using the Safe Senders tab in the Junk E-mail Options dialog box) or by using an existing message from the sender (click the message; select Message, Junk E-mail; and then select either Add Sender to Safe Senders List or Add Sender's Domain [@example.com] to Safe Sender's List).

Blocking Senders

If you notice that a particular address is the source of much spam or other annoying email, the easiest way to block the spam is to block all incoming messages from that address. You can do this using the Blocked Senders list, which watches for messages from a specific address and relegates them to the Junk E-mail folder.

As with Safe Senders, you can specify a Blocked Sender either by entering the address by hand (using the Blocked Senders tab in the Junk E-mail Options dialog box) or by using an existing message from the sender (select the message you want to work with and then select Message, Junk E-mail, Add Sender to Blocked Senders List).

Blocking Countries and Languages

Windows Mail also has two features that enable you to handle spam with an international flavor:

• Spam that comes from a particular country or region If you receive no legitimate messages from that country or region, you can treat all messages from that location as spam. Windows Mail does this by using the top-level domain (TLD), which is the final suffix that appears in a domain name. There are two types: a generic top-level domain (gTLD), such as com, edu, and net; and a country code top-level domain (ccTLD), such as ca (Canada) and fr (France). Windows Mail uses the latter to filter spam that comes from certain countries.

• Spam that comes in a foreign language If you don't understand that language, you can safely treat all messages that appear in that language as spam. The character set of a foreign language always appears using a special encoding unique to that language. (An encoding is a set of rules that establishes a relationship between the characters and their representations.) Windows Mail uses this encoding to filter spam that appears in a specified language.

In the Junk E-mail Options dialog box, display the International tab and use the following techniques:

• To filter spam based on one or more countries, click Blocked Top-Level Domain List, activate the check box beside each of the countries you want to filter, and then click OK.

• To filter spam based on one or more languages, click Blocked Encodings List, activate the check box beside each of the languages you want to filter, and then click OK.

Email Phishing Protection

Internet Explorer Phishing Filter works well if you stumble upon a phishing site while surfing the Web. However, most phishing "lures" are email messages that appear to be from legitimate businesses, and they include links that send you to phishing sites where they hope to dupe you into giving up confidential information. To help prevent you from falling into that trap, Windows Mail includes an anti-phishing feature of its own: If it detects a potential phishing email, it blocks that message from appearing. This feature is controlled by the Phishing tab in the Junk E-mail Options dialog box, shown in Figure 6.26. Note, too, that you can also redirect potential phishing messages to the Junk E-mail folder by activating the Move Phishing E-mail to the Junk Mail Folder check box.