Add a reminder through email
To set a reminder on an email that you send into Evernote, add the exclamation point (!) symbol into the subject line. If you wish to add an alarm to the reminder, after the exclamation point add the word tomorrow, or a date with numeric year, month, day separated by slashes.
The format is:
Email Subject: [Title of note] ![optional date for reminder] @[notebook] #[tag]
Email Subject: 5th-Year Celebration !2013/06/24 @events #anniversary
More about how to use reminders