Writing an engaging subject line is already tricky enough and if certain SPAM trap words are used, can mean increased chances of being filtered out of your recipient’s inbox.

There are wide-ranging reasons SPAM filters can be triggered, which cause an email to skip the recipient’s inboxes with one of the easiest solutions is by carefully selecting the words you use in the subject line.

Below is a list curated by Hubspot of a few key subject line words to avoid:


  • Clearance
  • Order
  • Order status
  • Orders shipped by
  • Buying judgements


  • Click
  • Click below
  • Click here
  • Form
  • Open
  • Sale(s)


  • Get
  • Give it away
  • Print out and send
  • See for yourself
  • No catch


  • Deal
  • Guarantee
  • Offer
  • Prize(s)
  • Unlimited
  • Free Trial


  • Certified
  • Congratulations
  • For Free
  • Guaranteed
  • Risk-free
  • Win


  • Call now
  • Apply Online
  • Offer expires
  • Get started now
  • Special promotion
  • Now only

Keeping this in mind, being aware of SPAM words will help you execute your emails better and get them into your recipient’s primary inbox. However, once your email reaches your recipient there is more to that for an effective email marketing campaign to get your reader to engage. For instance, structuring the content and understanding your email marketing objectives.

Email marketing is vital if you are determined to improve on your sales and to a larger extent get a positive ROI.