Not Being Able to Send Assignments to Students

[amagee 0]

I have had my students use evernote in class for a little over a week. They have been using it to take notes, and today I wanted to send them all an assignment into their evernote account by using the email feature. This worked fine in the morning, but this afternoon I tried to do the same thing and a message at the bottom of my screen kept saying "could not send email" even though earlier that email was working and was correct. Any ideas? Thanks!