Below is an example of a lottery scam email. Any reputable lottery company is not going to inform the winners via a random email. Also notice the "hotmail" email address. Another tell-tale sign of a scam.
Rule of thumb: mark this one as SPAM and delete it! If it sounds too good to be true, it is probably a scam!

Example scam email:

Date: Fri, 28 Sep 2007 21:00:04 -0400
From: "Mrs. Diana Banker"
Subject: Ref No: BOL-C/ 18-F0672312
Ref No: BOL-C/ 18-F0672312
Batch No:801/00515/HOP
Zonal Draw No: GMLA2-006
Grand Draw No: 15021

Attention: Lucky Lottery Winner,

We are pleased to inform you that your email address was selected among
the four lucky winners of British International E-Lottery Promotion
Sweepstakes held recently as part of our Experimental Bonanza. Winners
were selected through a computer ballot system drawn randomly from a pool
of over 100,000 names of e-mail addresses from World Wide Web in all
over Europe, America, Asia, Australia, New Zealand, Middle-East, parts
of Africa, and North & South America.

You have therefore been approved to claim a total sum of 250,000 GBP
(Two Hundred and Fifty Thousand Great British Pounds) in cash credited to
file BOL/9023110508/02. This is from a total cash prize of
1,000,000.00 GBP shared amongst the four (4) lucky winners in this category.

To file for your claims, please contact our claims director (Mr.
William Freetown) who is to guide and facilitate the release of your funds.
Ensure you provide him with the requested information below:

* FULL NAMES:
* CONTACT ADDRESS:
* TELEPHONE NUMBER/FAX NUMBER:
* AGE:
* OCCUPATION:
* NATIONALITY:
* BATCH NUMBER:
* REFERENCE NUMBER:

Mr. William Freetown
Claims Director,
Email: williamfreetown5@ hotmail.com
TEL: +447011132785

Regards,

Mrs. Diana Banker
Online Coordinator.

Door-to-door salesman should always be treated a bit more cautiously in general. That said, we recently read about a heating bill energy scam where folks were receiving offers from the mail, door-to-door salesmen and unsolicited phone calls. The scammers offer to save you tons of cash on your heating bills.
After you sign-up, you find out your bill is actually higher due to new fees and hidden charges with the new company.

Rule of thumb... ALWAYS check a company's credentials with the Better Business Bureau before signing up. Unless you are consuming huge amounts of energy per month, most of these alternative suppliers are not going to save you money.

eBay Email ScamWe saw this one come across our desk a few months back when one of our team members had a bunch of active listings on eBay. He got home one day and found an email in his inbox regarding a "Question from a seller". It had a link to log in and read the question.

Ok, sounds legit. You're selling on eBay, you get questions from sellers on occasion. Well this one is a complete scam. He came to find out, after he clicked on the link to "login", he noticed the URL of the destination site was NOT eBay.com. It was some random IP address like "233.121.1.23". This should be a sure sign that the email is a scam. Whenever you see the link that is not the authority domain name they are claiming to be, be on the alert!

If you really want to know if an email is legit, you can always go directly to the site (eBay.com or whatever) and contact them directly referencing the email. They can confirm whether or not the request is legitimate.

Moral of the story, be sure to check the destination URL of any links you are clicking in an email from eBay. Due to the size of the eBay user community, more times than not they are scams.