From Evernote,

Evernote Tip: Sending Email into Evernote
You just emailed a note into your Evernote account. Well done!

Here’s a tip: Evernote can automatically tag and file notes you email based on the content and subject. To enable Smart Filing, go to your Personal Settings.

Or, you can send notes into specific notebooks and assign tags by adding some simple information to the subject of the email. Here’s how:

Notebook: Add @notebook name to the end of the subject line.
Tag: Add #tag name at the end of the subject line. This feature works with existing tags in your account.
Be sure to follow this order: subject, notebook name, tags.

To add some text to an existing note, put a ” +” at the end of your subject line and we’ll place the body of the email into the most recent note with that title.

An example subject:

Fwd: Recipe for Bouillabaisse @Recipes #soup #fish #french

The Evernote team