If you've received an email from HubSpot notifying you that one or more of your lists has been quarantined, your list(s) had abnormally high hard bounce rates (15% or higher) in multiple email sends. High bounce rates can harm your sending reputation and affect email deliverability for all HubSpot users. A hard bounce rate of 1% is typically considered normal in the email industry.
Once the contacts on a list have been quarantined, you will not be able to send marketing emails, including automated workflow emails, to those contacts. It's important to note that quarantining is done at the contact level vs. the list level, meaning that if quarantined contacts are also present in other lists, they will be dropped when sending to those lists. Contacts on quarantined lists who have received, opened, or clicked one of your emails, or have opted in via a signup form will be exempt from the quarantine; you can continue sending to these eligible contacts.
What should I do next?
High hard bounce rates indicate an issue with the health of a list. This could mean that your email was sent to an older list with outdated addresses or one including contacts from a purchased list, or that your email received an inordinate amount of spam complaints. This is a good opportunity to evaluate your methods for collecting contacts and lists. To do so:
- Confirm that your list meets the criteria here.
- Import any opt-out lists from other email systems into HubSpot.
- Remove any contacts from your list who haven't heard from you in over a year:
- Navigate to Contacts > Lists and create a new smart list.
- Set the criteria to Contact property | Last email send date | is more than | 52 weeks ago.
- Exclude that list from each of your email sends.
For more information on email deliverability best practices, check out this article.
How can I see all the contacts in my account that have been quarantined?
- Navigate to Contacts > Lists.
- Search for and click on the smart list titled Quarantined Contacts.
If you are able to verify that some of your quarantined contacts have valid email addresses and you've successfully reached out to them outside of HubSpot, please contact HubSpot Support.