Parsing a text file of multiple emails

[Matthew Brender]

Hello all - I'm getting into coding with ruby and want to start with getting some insights from a set of archives. I have a text file imported and passed using: 

mail = Mail.read_from_string(full_file)

My goal is to separate the different threads of this flat file and I'm curious if mail is the right tool or whether some ugly regex is the only option. The format looks like: 

From: user at site.com 

Date: Thu, 22 Jan 2015 17:59:31 -0500

Subject: This is an email subject 

Message-ID: Clalalalala...@mail.gmail.com>

<< Body >> 

The result shows 0 for mail.parts.length and I don't see a way to start that process of parsing. What would this group of folks recommend? 

All code is contributed here: https://github.com/mjbrender/ruby-parse-mail/blob/master/parse.rb

Thanks so much, 

Matt