[Exim] exim quoting the word "From" in emails

Hi All,

We are using exim-3.36 and currently when ever you send an email in plain
text that beings with "From randomtextgoeshere" it appears that exim inserts
a ">" in front of the word From so it appears like this.

>From randomtextgoeshere

It looks like exim is trying to quote it somehow? It only applies to plain
text and happens with all mail clients (OE, linux mail, raw spool file).
I've tested this on another exim server we have running 3.36 and it doesn't
have this problem. I also tried turning off our filter spec file and it
didn't help either. Has anyone seen this before or can recommend any places
to look for answers?

Any help would be great