These are the instructions for a Gmail account, to find the instructions for another service try searching for the SMTP settings for that email service. The set up should be very similar.

First Log into the camera using a web browser. Then go to Configuration>Network>Advanced Settings>Email. Then input all SMTP settings for your email service.

After entering the SMTP information go to Event>Basic Event>Linkage Method, and make sure “Send Email” is checked.
The only thing you need to do to finish up the email notification for a Gmail account would be:
1.            Log into Gmail-go to settings- Select Forwarding and POP/IMAP- POP Download: Enable POP for all mail (even mail that’s already been downloaded)
2.            Select Profile icon- Click on My Account-Sign-in & Security-Connected apps & sites-Allow less secure apps: ON
After doing these two things if everything is set up correctly it should work.
Once you have that set up and working correctly you can add another receiver like Yahoo if you would like.