Top 3 Spam Keywords to Avoid in Email Subject Lines

spam keywords to avoid in subject line

Loading your email with spam keywords, which are identified by the majority of email marketers and service providers, as the common keywords used in a spam email, is the fastest method to end up in a junk or spam folder of a subscriber.

Subject lines of an email are just one segment belonging to the equation of an email delivery. Based on content, reputation, and most above all, subject lines, emails are delivered to recipient’s inboxes. Engagement, in many cases, is also applied to such SPAM FILTERS.

Writing your email’s subject lines can be a very stressful task. There are numerous spam keywords, which are potentially blocking your path to client’s inbox. By avoiding some trigger words in subject lines of your email, you can witness a dramatic increase in your chances for moving beyond the SPAM filters. The punctuation and keywords, which we use in the email subject line, are very significant. If you send a decent amount of emails through your marketing campaigns, your emails are highly prone to ending up having issues related to SPAM filters.

Every marketer must have a ‘NOT TO INCLUDE’ list of spam keywords right next to them while writing an email. While it is well-known that a particular trigger keyword for the subject line used once in a while, will certainly not hurt your rate of delivery, but it is considered wise, if you think practically and find good synonyms.

The spam filters assign ratings to email newsletters. For instance, usage of word ‘Free’ in the subject line of your email with an otherwise absolutely harmless email may help you with sliding through your recipient’s inbox if you have a better delivery record. However, if you try the same technique again and replace the subject line with all in CAPS, your email may end up in SPAM BOX.

Usage of the word such as FREE is discouraged by a few, however, we suggest you to use them rarely or by combining it with random trigger words such as ACCESS, TRIAL, SAMPLE, etc, which can glide your email into JUNK BOX. Using ‘FREE’, in fact, increases the opening rates after delivery.

Top 3 ‘NOT TO INCLUDE’ Spam Keywords:

“Whitepaper,” “Report, or “Journal

Folks from sales and marketing may argue that JOURNALS, REPORT, and WHITEPAPER, are often offered to recipients in order to provide value, but in order to make it highly effective, recipients need to be receptive to this content in a unique manner. This is because most of the people prefer searching whitepapers, journals, and reports online. Try using a unique subject line instead of whitepaper along with a trigger word, if you wish to send whitepapers through email.


Do not use this term in the subject line of your email, ever. The word ‘EARN’ is frequently associated with fraud plans related money-making, which makes it easier to be filtered as SPAM.


There aren’t many things, which can be guaranteed in life. So, it is quite natural for recipients to be skeptical about the word “GUARANTEED”, which will offer them an excuse to dump your email out of their inbox.

According to ReturnPath’s research by, the index of permission-based marketing emails sent via legitimate marketers that hit the inbox is 79%.

Spam keywords can be triggered for various reasons, which might cause your email to land directly in SPAM box of your recipient. One of the easiest techniques to avoid landing yourself in ‘SPAM TROUBLES’ during your email marketing campaigns is by carefully selecting the keywords and phrases to use in subject lines of your marketing emails.

Subscribe to FrescoData Blog for more email marketing tips and tricks. 

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