Thank you for reaching out to the Constant Contact Community. I’d be happy to assist you today.
Do you have a few examples of email addresses you are having issues with? E mail us at social_support(at)constantcontact(dot)com with your account username, a reference to this post, and some examples and w e can take a quick look at them for you! It is possible there was already a contact record with the correct email address, as well as the incorrect address. That would give you that error when trying to fix it. It would not make any difference whether a contact was on several lists.
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