I can receive email but can't send it out

[Android Central Question]

I haven't sent out the email for a while but I still get it very often, like every day until 3 day ago, I tried to send one out, but it keeps telling sign in failed

 

[B. Diddy]

Welcome to Android Central! Which phone, which email app, and which email provider? If you added an non-Gmail account to the stock Email app, make sure the outgoing SMTP server settings are correct.