Spam Filter Trigger Words -- Are they important?

As the holidays approach, I think it's a great time to talk about spam words and phrases that could trigger ISP spam filters and create deliverability problems for marketers. I've asked my esteemed colleague, marketing consultant (and deliverability expert) Josephine Garcia, to weigh in. Here's what she had to say:

I've often heard that using words like 'Free' and 'Viagra' will get your email delivered to the junk/spam folder. My response is, it depends. What does it depend on? It depends on two things: First, it depends on your sender reputation and second, it depends on how you use those words in combination with other words or phrases.

Spam filters are a way for ISPs to determine which emails should be delivered to the inbox vs. the spam or junk folder and typically use a series of rules that look for words or phrases that are associated with spam. Points are assigned for each word or phrase found in the subject line or body of an email.

A popular filter used by some ESPs for internal testing and ISPs for mail received is SpamAssassin. SpamAssassin considers any email that scores 5 points or more to be spam.

Below are a few examples of SpamAssassin rules and the points assigned to each:

Mentions a generic version of a certain little blue pill (1 Point)
Almost looks like talk about a certain little blue pill (2+ Points)
Phrase: F R E E (2+ Points)
Subject has exclamation mark and question mark (.201 points)
Subject starts with dollar amount (2.449 points)

The above assignations may not seem significant, however, when any combination of words or phrases that score points is used in an email and compounded by poor data hygiene practices or sender reputation, the likelihood of inbox placement is slim to none.

On the flip side, a large reputable pharmaceutical company that properly authenticates and brands their emails, employs good data hygiene practices, and has high user engagement metrics which happens to market that type of medication may have consistent inbox delivery. Similarly, a big brand marketer that sends daily deals and frequently uses subject lines that start with dollars signs but has a good sender reputation will also have consistent inbox delivery.

Want to improve your chances for inbox placement this Holiday season? Here are a few recommendations:

Ensure that you have all levels of sender authentication in place
Remove subscribers that have not engaged with your emails in more than 18 months
Send welcome emails to new subscribers
Target your campaigns based on subscriber behavior and interests
Send timely, relevant email campaigns
Honor unsubscribe requests promptly

Doing so will ensure that flashing lights and bells stay on your tree, not on ISP spam filters.

May all your emails inbox during this Holiday season!