- If your email is set to send to more than one list and you have contacts that may be on more than one of the selected lists, HubSpot will automatically de-duplicate based on the email address.
- Your recipients will only receive one copy of the sent email. You can test this by adding your personal email address to multiple lists (if you are not already a contact, add yourself under Contacts > All Contacts > Add contact) and sending an email to those tests lists.
- This is also true if you use the Send to more feature on the post-send performance page. If you use this feature to add another list after the initial send, you do not need to exclude the list(s) of contacts you already sent the email to, as no contact can receive the same email twice. If a contact is on the original email send list and is also on the additional list you are sending to, they will not receive the email a second time.
Please note: there is an exception for follow-up emails and emails that have been saved for automation. Contacts can receive form follow-up emails more than once if they fill out the associated form multiple times. Similarly, contacts will receive automated emails as many times as they are enrolled or reenrolled in a workflow including that email.