Add 'From:' as a delimiter to remove uneccessary email headers

Some email responses are slipping through with email header fields.  For example, a response sent as such:

>I will check availability and get back to you shortly. 

>John

>From: Widget Corp [mailto:contact@widgetcorp.com] 
>Sent: Wednesday, November 13, 2013 8:17 PM 
>To: john@j.com
> ---- REPLY ABOVE THIS LINE -----

will include the whole From: bit.  

Awesome gem by the way.