Email::Simple's main job is to take a message and parse it. That's all it really does, aside from reconstruction. Many payloads are RFC 2822 compliant-ish messages. Someone asked me if ever there was a plan to abstract the generic guts of Email::Simple, which is most of it, actually, into something like Parse::RFC2822CompliantMessage. I certainly didn't have any plans to do so.
I'm curious if this is something other people would find interesting. I think that, in terms of implementation, I wouldn't have Email::Simple rely on this module. Instead, I would mirror the abilities of Email::Simple into a new module, for which a decent name would be highly requested.
In any case, are you looking for something like this?