Radiusbob has an email dropbox address for you to use to push emails from outside of Radius into your lead/client's file's Notes page. The dropbox email is found in your Account> My Information> Dropbox.
Please note that email attachments will not be brought into the file's notes. The max email size to be imported into the Notes is 25 MB. If you get a bounce back from the dropbox system saying that your email was too large for import, that is why.