[Android Central Question]

I have a samsung Galaxy j3 & when i try to send an email it says sending failed error occurred on email server

[Rukbat]

Assuming it's not an error on the email server, about the only solution is to delete the email account from the app, then install it again. If you join the Android Central community so that you can post here (if you don't, every post starts a new thread, and since you're listed as "Android Central User", it's almost impossible to find your previous posts), and post who your email provider is (we don't want your email address, just the provider - Google, Outlook, Yahoo, etc., someone using them can see if they can send an email and, if not, let you know that it is a server problem. If it's Google (gmail) I can tell you that it's not their problem - I just sent emails between 4 of my accounts, both ways each, and they went.

[B. Diddy]

Welcome to Android Central! Which phone, which email app, and which email provider? If removing the email account and adding it back doesn't work, as suggested above, then you may need to check the SMTP server settings for that account (within the email app's settings) and make sure they're correct for your email provider.