To resend an email to supporters who should have received your email previously but hard bounced...
- Clone the previously sent email blast.
- In the Select the Audience section, choose the Use a custom supporter query option.
- Update your rules for the query...
Supporter Fields Email contains Gmail
AND
Email blast history bounced [that previous blast] - Once you set the query up, the target count will be provided. You can then schedule and send out the blast to the new targeted records.