Hi, how is it going? It appears that you are still offline and you have not provided the information I was asking from you. Without those information, I can only provide very limited procedures to help you fix your problem.
I am very sorry about your email issues.
I believe there is a problem on your email account so your email app stopped working. That is, using your email app, you are no longer able to send and receive emails.
To fix this problem, you need to access your email account using a web browser instead of the email app that you used to use. For instance, if you are using Gmail, you use a web browser and go to www.gmail.com and then sign in to your email there. If you use Hotmail or Outlook.com or @msn.com email account, go to www.hotmail.com and sign in there.
If you cannot login because your known password ***** ***** or rejected, click on the Forgot Password ***** to reset the password. When successful, you can then create a NEW password ***** access your email account.
After having a working password, please UPDATE the password ***** the email app that you are using. If there is no way to update the password, just DELETE the email account from your email app or phone, and then ADD it again using the new password ***** created. That should sync all your emails back.
Thank you and I hope that helped. If you need further assistance, please let me know so that I can assist you further.