Understand and manage quarantined contacts

Contacts with suspicious marketing email or form activity, such as repeated spam complaints or bounces, may be quarantined by HubSpot. These contacts will remain in your account, but be dropped from future marketing email sends, including automated workflow emails. If you have the Transactional Email Add-On, transactional emails will be sent regardless of quarantine status.

Understand why contacts are quarantined

HubSpot will quarantine contacts from an imported segment or after a marketing email send if any of the following conditions are met:

• The contacts directly contribute to a high hard bounce rate on multiple emails or a critically high hard bounce rate on a single email sent through HubSpot.
• The contacts generated spam complaints or widespread bounce reports from other email services.
• The contacts have email addresses with a known history of high hard bounce rates based on HubSpot's historical email data. These emails are also referred to as global bounces.
• The contacts were added through suspicious form activity. This scenario is most likely caused by a third party with the intent of spamming the recipients' inboxes. 

The following types of contacts will be exempt from the quarantine: 

• Contacts who have opened or clicked one of your marketing emails.
• Contacts who opted in through a valid form submission.
• Contacts who have replied to a one-to-one email sent from a connected inbox, including sequence emails.

View quarantined contacts

You can view quarantined contacts in the Quarantined Contacts segment created by HubSpot, or in a segment you create that filters for quarantined emails. 

View the default segment of quarantined contacts

1. In your HubSpot account, click More, then navigate to CRM > Segments. If More doesn't appear in your account, navigate to CRM > Segments directly.
2. Click the segment named Quarantined Contacts.

Create a segment of quarantined contacts

1. In your HubSpot account, click More, then navigate to CRM > Segments. If More doesn't appear in your account, navigate to CRM > Segments directly.
2. In the top right, click Create segment.
3. Enter a segment name, then click Next.
4. In the segment editor, click Add filter in the left column. 
5. In the center column, click Contact properties. 
6. Select the Quarantined Emails property. 
7. In the center column, click the dropdown menu and select is known.
8. In the top right, click Review and save. 
9. Finish setting up the segment details, then click Save and process segment. 

Remove contacts from a quarantined segment

Once a contact has been quarantined, they must re-engage with your content to be removed from a quarantined segment. Contacts cannot be manually removed from quarantined segments. 

To prompt individual contacts to re-engage, you can either: 

• Send them a one-to-one email from a connected inbox. If a contact replies to a one-to-one email where they are the only recipient, they will be removed from the quarantined segment. 
• Have them submit a HubSpot form. 

A contact who has been removed from a quarantine segment may still be dropped from marketing emails for other reasons, such as hard bounces. It's recommended to validate all contacts on a quarantined list with an external email validation service. 

Prevent future issues with forms

If your contacts have been quarantined due to suspicious form activity, it's recommended to take the following steps: 

• Add CAPTCHA to your forms to help prevent bot submissions. 
• Turn on double opt-in to require that new contacts verify their email address.