This is usually from the email application and it happens whenever one wants to send email messages.
When this error message displays here is what you should do.
If you haven’t done the force stop, and clear cache thing, then you should do that first. To do this go to,
Settings > Applications
Manager > All > Hold on the email logo for 2 secs and then release it.
Now you can Clear Data and Force Stop.
Next time when you launch the Email Application, you will be asked to set up the email accounts again.
If this doesn’t work here is the second method.
2. You need to send an email from one account to the other and leave it in your inbox.
3. If you’re using Samsung device just do the following.4
Download Samsung kies to your computer, then plug your phone to it, use it to update your device’s firmware.
4. One Funny thing Android does is to send you notification to upgrade to the latest operating system which is Marshmellow.
If you’re not on the latest OS. Then do this to solve the unfortunately Email has stopped error.
Go to Settings > App Manager
Look for Android System WebView.
Uninstall it , clear cahe and disable it.