If your computer or mobile device is having problems connecting to your email, especially if the error is password failure randomly one day, Microsoft Office 365 has probably forced your password to reset.
Best solution is to reset your email password:
1) open your web browser, and visit the email server directly by going to https://portal.office.com or webmail.townlife.com (and clicking the large red 'Office 365' cloud).
2) login using your email address and password
3) If your login failures the error message will look something like this, simply click 'reset it now' or 'forgot my password'.
4) As long as you setup your account once with the server properly, then it should have stored an alternative email address and your mobile cell phone number. Use either one to reset your password!
5) Once your password is reset, you can now access it from your computer or cell phone with the NEW password!