How many times have you used the words and terms: free giveaway, free book, book sale, discount?
I have definitely used them, and I would guess that most of us have. Using these words will not necessarily land you in everyone's spam folder, but it could increase the possibility. Spam filters are set to various strength protection levels and some are more strict than others. Keep in mind that they scan more than the headline or subject line, but the entire email or blog post.
As technology has increased and evolved, spam filters now take into consideration many algorithms besides word and term usage, such as the IP addresses and domains to determine a poster's reputation. For instance, you might get away with using a specific term a few times, but if you are sending out multiple sessions of emails and posts from your domain or IP on a constant basis with the same terms, your info could get flagged and may start landing in spam filters. Other factors include abuse complaints and content scores.
Recently, HubSpot posted a list of commonly known words and terms that should be used minimally to keep your posts from going to the spam slush pile, The Ultimate List of Email SPAM Trigger Words. It's quite extensive and broken down under specific categories. Once you browse through this list, you may be left wondering what you can use! Keep in mind that this list doesn't mean you can never use these words, but you might want to limit them. It's just like the cliches in writing that we should only use sparingly and for the right circumstance.
It's best to keep your subject line short and to the point at 50 characters or less when possible. While you might want to establish branding your newsletter, if you use the same subject line each time, it will decrease the open rate. For example, News from Author Raymond Smith as the subject line each time, doesn't distinguish it from previous emails. What is different about this email than last month's email that would entice me to open it? Be creative, but not deceptive like the cliche of a used car salesman.
- Sending out too many emails within a given hour or day.
- Too many exclamation points.
- Using all caps.
- Coloring fonts bright red or green
- Design a Word doc and converting it to an html file
SpamAssassin is one of the best known spam filter for internal testing used by most marketers. Any email that scores 5 points or more is considered to be spam.
For More Info:
Best Practices for Writing Email Subject Lines
Spam Filter Trigger Words - Are They Important?