Thank you for reaching out to us! That is a great question. The easiest way to delete a contact or search to see if its already in the account, is to click on Contacts in the top left of your account. From there you can use the search bar on the left-hand side and it will bring up all the information it has on that address. You can click here to see all the steps involved in removing the email address!
Please let us know if you have any questions or concerns going forward!
I did the same but after this also I could not add the same email address again and also please read the question again, I mentioned API. But I tried both API and manually deleted as like you mentioned but no solution.
Thank you for responding with these details. I apologize if we misunderstood your original post and want to make sure you’re assisted. Please email us at social_support(at)constantcontact(dot)com with your username, the email address you were trying to add, and a reference to this post.