This will be a symptom of the same problem that I am experiencing. If you clear all data for the Connect app you will be able to connect again for a short period of time. The app will quickly lose its connection to the server and you will see the message "we were unable to process please try again later" or "Connection could not be established, please try again later". See my post titled "Xfinity Connect app not staying connected". Let's hope they pay attention to this forum and address this issue.
I have just been in contact with Xfinity and they have affirmed that they are in fact having an issue with email services right now. They have told me that it will be resolved within a few hours. Hope this fixes the mobile app issue also.