Are you using HubSpot's graymail suppression feature to exclude 'Unengaged' contacts from receiving emails?
What is graymail? Graymail is email that contacts have opted in to receive, BUT never opened/clicked any email (or go an extensive number of sends without opening an email).
Spam filters can identify and filter out emails that your recipients aren't opening or clicking. This increases the likelihood that future emails will end up in the junk folder or spam filter. By continuing to send email to contacts who don't open or click, you're lowering your overall sender score and damaging your email reputation.
The HubSpot feature: Using the 'Sends since last engagement' property, HubSpot's graymail suppression feature automatically excludes any contacts who have not been engaging (are 'Unengaged') with your marketing emails.
A contact will be categorized as 'Unengaged' if they:
- Never opened a marketing email from you and hasn't opened the last 11 emails you've sent them. (OR)
- Previously opened a marketing email from you but haven't opened the last 16 emails you've sent them.
You can enable or disable this setting for any individual marketing email!