This is September 2018 and I'm having the same issue. Also, I keep confirming my email and never get the confirmation link. I've checked SPAM folders, and all other folders.
I apologize that you are having issues with the Join My List app. Are you seeing an error message, and if so what does it say? Can you try to do this function in a different browser? Also, do you have a different Facebook administrator that could try connecting the Constant Contact application?
Are you trying to add a new email address to your verified email addresses in your account? If so you must first send the verification email and then it will let you confirm the address.
Let us know if you need any further assistance!
Thank you for contacting us. Right now, it looks like our engineers are still working on the source of the problem. The suggested workarounds are to try connecting the JMML integration through another business page administrator or to try and add it while using an alternate browser. I have added you to the list to be notified when the issue is resolved.
I apologize that you continue to have issues with the Join My List app on Facebook and appreciate that it is important to your business to have this feature working properly. I am happy to continue to troubleshooting your issue but did want to clarify the troubleshooting you've performed. Have you tried using different browsers and are you a Facebook page administrator as this is required to include the app on your page? Were you seeing an error message? Could you attach a screenshot of the step that causes the issue during the connect process?