On my HTC M9 my mail keeps getting message login failed, how can I fix this?

[AC Question]

on my htc m9 my mail keeps getting message login failed how can i fix this

as above how do i fix this

 

[B. Diddy]

Re: on my htc m9 my mail keeps getting message login failed how can i fix this

Welcome to Android Central! Are you talking about the stock Email app? What's the exact error message, and where and when does it appear?