Evernote recently changed its policy so you'll need a premium account to use the Email to Evernote feature more than five times a month. Thankfully, Digital Inspiration points out you can get around this limitation with If This Then That.
If you're using Gmail on desktop, you can use Evernote's Email Clipper to send Gmail messages over to Evernote. Otherwise, you can use two different IFTTT recipes to do the same job. This one forwards any email message with the #Evernote tag in the subject line to your notebook, and this one sends any note with the label Evernote to your notebooks. It's not as feature-rich as the premium feature, but it does the job.
Evernote Drop Email-to-Note for Free Accounts, Alternative [Digital Inspiration]