Email user at some point of time has the face the issue of not able to login into their email account. There are few reasons which are listed below why a user sometimes not able to login.

  1. Server is down.
  2. User have put wrong information.
  3. User didn’t use account from very long time.
  4. Password is incorrect.

https://www.roadrunneremailsupports.com/roadrunner-email-settings/