As a legitimate marketer you should try and avoid that  your newsletter and email shots get seen as spam by following these basic guidelines:

1. Add Value: By far the most important is to add value to your reader's life, by adding value your readers will look forward to your next newsletter.
2. Keep your mailing list up to date. Quality contacts and real leads take precedence over the amount of email addresses on your database. Therefore, tracking and executing change of address, inactive addresses and subscriptions and gathering new leads and addresses is invaluable.
3. Have a clear 'unsubscribe' button or link. Allowing readers to unsubscribe is important. You don't want angry readers unable to unsubscribe, as this could lead to your being reported as a spammer.
4. Avoid 'spammer' mistakes, such as including too many links or stuffing your newsletter with irrelevant adverts. The more you look like you're advertising, the more likely readers are to unsubscribe or delete your mail.
5. Keep it short. Attention spans wander, especially on the Internet, and you don't want to lose your reader before you get to the hook. 400 - 500 words is plenty, and some people recommend as few as 250 words per mail!
6. Keep it simple and concise. You don't have to use big words and industry jargon. It can make you look pretentious and turn your readers off.
7. Check spelling, grammar and links. Bad spelling makes you look stupid, no matter how good the content - it's as simple as that. And links that don't work are annoying and unprofessional.
8. Keep your tone conversational and friendly. Think of yourself as a benevolent mentor rather than a salesperson. Talking to your readers as equals will make your product easier for them to relate to.
9. Be consistent in your frequency, layout and format. Your readers should recognise what they're seeing and know what to expect from you.
10. Send from a recognisable email address. If your readers recognise your address they will know your email is not spam. A recognisable address can also be used by readers to override automatic spam blockers by adding your email address to a 'safe senders' list.
11. Make it easy to forward. The easier you make it for your readers to share your letter, the easier it is for you to gain new subscribers. A 'forward' option is the electronic equivalent of a word-of-mouth recommendation.