I am getting an error "We could not verify your authenticated senders ID" whenever I am trying to send any campaign. How do I resolve it.
If it is having issues with you authenticated sender ID it means that the email authentication you set up with constant contact was not able to be verified or there was an error. Our Deliverability team will be able to help resolve this issue. You can reach them here.
Here is some more information about Authenticated Emails.