If you are certain that you are emailing a target list of constituents that belong in that center, then the issue is probably that you are trying to email constituents who's Security Category does not match the Security Category of your Email Campaign. You can change the Constituent's Security Category by editing their Constituent360 profile under Biographical Information.
  1. Go to Constituent360 > select Constituents
  2. Search for your constituent and click the Edit icon Edit
  3. Look for the Security Category field and adjust the drop-down menu to be in the same Security Category as your Email Campaign
  4. Click Save
    • If you don't see the Security Category field here, then please Contact Support and provide the solution ID so that it can be enabled.
If you need to change the security category for constituents in mass, then you can do a mail merge to export the constituents and include the security category field. Then change the value in the security category column to be the ID of whichever one you want and do a Custom Constituent Import.