(Warning: today's entry contains material that may be offensive to some readers. Particularly if you don't understand satire).
1. Pay particular attention to your mailing's subject: Always use exclamation points (!), CAPITALIZATION, the words "free" & "guaranteed", and/or gappy text (t h i s i s g a p p y t e x t). This will help me identify the mail as being legitimate.
2. Use generic salutation formulas such as "Dear User", so that I know that you are someone I know and can trust.
3. If you use a title, make sure the title is confusing. That way I have to open the mail to see what it is.
4. Include a disclaimer stating that your email isn't SPAM, and ALWAYS claim compliance with some legal criteria, especially one that is not actually law in my country.
5. Include gratuitous references to SPAM subjects. Talk about Rolex watches, sexually oriented activities, Rx drugs, or debt treatment. An email which mentions all of the above in one email will very surely get a response from me; chances are I will need at least one of your products at some point in my life.
6. Always offer me a free gift if I forward your message to all of my friends or follow your link. Make it an expensive gift so that I will know that you are serious; be careful to make no reference to the terms and conditions of your gift.
7. Make sure that the product you are selling is one I would never need, or even use. Kudos to the SPAMmer who wrote me to tell me that my account at WaMu was suspended until I followed their link and signed into my account...I am Canadian, and therefore do not have an account at that bank.
8. Use poor grammar (eg. "their" for "they're"). Nothing lends credibility to your cause like a big dose of stupidity.
9. Use poor spelling, so that I know that you care enough about your cause to forget to use spell-check, or even a dictionary ("Looses" is not the same as "loses," and when used as a verb means "to let loose," or "to free from restraint." Granted, "loses" does rhyme with "chooses," which does have two "o"s, but such inconsistency is the price we pay for not speaking Esperanto).
10. Punctuation is overrated. Although you used 15 exclamation points (!) in your title, don't bother with any in the body of your letter. I like a challenge, so the more confusing you can make your mail, the more accomplished I feel when I decipher it.
11. I like it even better when you eliminate all capital letters. Reading a letter without capital letters AND missing punctuation makes it really interesting, as I have to figure out when you have started a new sentence.
12. Put at least one confusing quote at the bottom of the e-mail, such as the one I received the other day: "Dolls always whizgiggled at me and even fellows did in the open water closet!Well, now I whizgiggle at them, because I took Me_ga. d_ik. for 3 months and now my pecker is terribly greater than world." If you are going to SPAM me, you may as well give me a good laugh while you're at it.
13. Sign your mail with a fake name. If you are selling Viagra, I suggest "Harry B. Humongous", if selling noise-canceling headphones, you could be "Balthazar P. Quietude", etc. It's your mail, so you can be whomever you want; I just ask that you be imaginative.