What is Phishing?
Phishing (also known as spoofing) is the act of attempting to fraudulently acquire sensitive information, such as passwords and credit card details, by masquerading as a trustworthy person or business (most common on the Net are eBay, PayPal, Amazon, Microsoft and many financial institutions) with a real need for such information in a seemingly official electronic notification or message (most often an email, or an instant message). It is a form of social engineering attack. The term phishing comes from the fact that Internet scammers are using increasingly sophisticated lures as they "fish" for user’s financial information and password data.

What is unwanted email?
Unwanted email, sometimes known as junk or spam email, is unsolicited email advertising.

Examples of unwanted email:

Adverts for porn or gambling sites.
Work from home schemes.
Online pharmacies.
Advertising “Herbal Viagra” and similarly improbable products.
Selling implausibly cheap (pirated) software.
A substantial majority of the email that goes over the internet every day is unwanted junk mail.

How spammers get your email address
Spammers collect addresses in many different ways, including:

Guessing. Spammers use automated software to generate addresses.
Harvesting from websites. If an email address is embedded in a webpage, spammers can use spiders (similar to those used by search engines) to find them.
Online registration. If someone gives their email address to a dodgy website or one with a lax privacy policy, the site owner can sell the addresses to spammers.
From other spammers. It’s possible to buy lists of email addresses by the million online.
So-called spam email cancellation services. These bogus services offer to block unwanted email but really collect addresses.
Why stop unwanted email?
It wastes bandwidth.
Filtering it manually is very time-consuming.
Unwanted email often contains offensive images.
It propagates online fraud, such as pishing.
Often contains viruses.
How to spot spam
Filtering email manually is time-consuming but here are some tell-tale signs you can use to do so if you only get a limited amount.

From someone you don’t know.
Contains weird misspellings (e.g. “p0rn” with a zero), designed to counter spam filters.
Offers something for sale.
The subject line and contents don’t match.
Contains a beguiling or urgent call to action (“Buy now to get 50% off”).
If you get more than a handful of unwanted emails a day, we recommend you use a mail filter to get rid of the rubbish automatically.

How to filter email
Choosing a new webmail account
If you plan to sign up for a new web mail account, look for a service that offers email filtering, including the following:

Google Mail (Gmail.com)

MSN Mail (Hotmail.com)

Yahoo Mail(Yahoo.com)

Hotmail, Yahoo!, Google Mail filtering
Hotmail: To switch on filtering, click on Options, then Junk E-Mail Protection, then Junk E-Mail Filter and select Enhanced.

Google Mail: filtering is enabled by default.

Yahoo! Mail: Click on Mail Options, then Spam Protection and then Save these messages in the Bulk folder, then Save Changes.

For other webmail providers, check if they have spam filtering and, if not and spam is a problem, consider switching.

Microsoft Outlook 2003
Microsoft® Outlook 2003 features automatic spam protection. To switch it on, select Tools then Options and click on the Junk Email… button.

Microsoft Outlook Express and other email clients
Outlook Express does not have a built-in filter. You have a couple of options:

Switch email clients. Mozilla Thunderbird is a free, open source email client that does almost everything that Outlook Express does (the main exception is Hotmail support) but adds additional features such as a spam filter. 
Buy a filter program, such as Cloudmark Desktop that works with Outlook and Outlook Express.
These are the same options for older versions of Microsoft Outlook. If you use a different mail client, see if it has a filter option or if you can upgrade it to a newer version which does. Alternatively, considering switching to a webmail or email client that has effective spam filtering.

Additional tips for dealing with unwanted email
Pick long or obscure email addresses, with a combination of letters, numbers and punctuation marks to make it harder for spammers to guess.
If you use a spam filter, report spam that gets through the system so that the filter can catch it in future.
Check junk mail folders regularly in case a legitimate email gets through by mistake.
Don’t click on links in spam.
Don’t open attachments in spam.
Don’t buy things or make charity donations in response to spam email. If people stop buying, the spammers will stop sending.
Don’t click on “remove” or reply to unwanted email.
There are no spam email opt-out lists. Anyone advertising one is trying to get your email address or money.
Only give your real, primary email address to people you know.
Don’t list your main email address in internet directories or other public sites. Don’t post it on your own website if you have one.
Set up a throw-away email address for online commerce and site registration using a free webmail service (see above).