A list will be quarantined if it directly contributes to a high hard bounce rate (15% or higher) on emails you've sent through HubSpot. A newly imported contact list may also be quarantined if our system detects a history of high hard bounce rates for the emails included on the list. 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. If those quarantined contacts are also present in other lists, they will be dropped when sending to those lists. Contacts on quarantined lists who have 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 This could mean that you have sent emails to lists with outdated email addresses, contacts from a purchased list, or received an inordinate amount of spam complaints on your emails over time. This is a good opportunity to evaluate your methods for collecting contacts and lists. For more information on best practices for managing your contact lists, 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.