Email has become a really complicated matter. There are tons of unwanted emails circulating every day, so there is spam detection software running on every email server, to check and block unwanted messages.

There are too many reasons why an email might be marked as SPAM, to list them all in this post. Remember that the email system is complicated and is mainly based on reputation. If your domain has a good reputation, then it’s less likely to hit a spam filter. You can build your domain reputation by following the good practices below:

1. Never (ever) use your email account to send out promotional messages, or any other kind of mass-mail! This will hurt your domain reputation. Sending a party invitation to 6 people is OK. But sending your new catalog/brochure/etc to your clients is NOT OK.
2. Avoid forwarding email messages you got from other people, about an unbelievable story. That will most probably be a hoax or some kind of practical joke.
3. Avoid placing many links or images in the emails you send, especially to controversial web site and services.
4. Provide a clean an descriptive subject for the email message, avoiding words and phrases like amazing, click here, congratulations, dear friend, great offer, order now, etc. These subject lines are usually sent by spammers.
5. Avoid using excess styling (different fonts all over, bold and italic in too many places, etc). Keep the content as clean and neat as possible.
6. Ask the recipients to add your email address in their contact lists.
7. Include your name in the email, so it is easier for the recipient to identify you