Why does my e-mail not get sent on my LG G3 cell?

[Kuraho]

When I hit the send button on my e-mail, at the top of the screen it shows "updating" and that never seems to end. My e-mail does not get sent

 

[B. Diddy]

Welcome to Android Central! Which email app and which email provider are you using? Does this happen on both wi-fi and mobile data?