For an Imported List
- Navigate to Email>Lists
- Search for and click the pencil icon next to the list associated with the email message
- Click View List
- Does the Email field contain the name instead of the email address?
- If so, upload an Excel list of email addresses, with the mapping correct
- Send a new message with the new list. If you cannot select or change the recipient list for an email message.
For all other scenarios
- Check the Invalid Accounts List. If the email address is on this list, and you've confirmed with the recipient their email address is truly valid, it can be removed.
- If the email address does not show on the invalid accounts list, this typically means they may have been added to the Blacklist. To check their email on the Blacklist and request its removal.
For more information:
What is a hard undeliverable email (hard bounce)?
What do email bounce messages and codes mean?