google apps script - Adding text to GMail message before forward -

i wanted add small text emails before forward them, little "notice" line. can add text/html part in html email, not in text/plain part. here's plan body of message:

content-type: multipart/alternative; boundary=20cf303ea8aab6b10304e1b6fd7e

--20cf303ea8aab6b10304e1b6fd7e content-type: text/plain; charset=iso-8859-1; format=flowed; delsp=yes

at last!!!!

--20cf303ea8aab6b10304e1b6fd7e content-type: text/html; charset=iso-8859-1

[this email forwarded 'forward many' gmail gadget, more info https://sites.google.com/site/replytomany]

at last!!!!

--20cf303ea8aab6b10304e1b6fd7e--

anyone know how/if it's possible it?

cheers.

if "forward" in gmail have not possibility add text orignal message prepended with

---------- forwarded message ---------- from: <amsmota.dev@gmail.com> date: 19 july 2013 11:00 subject: fwd: beta test to:  

i exact same thing, should open request this? seems such trivial thing strikes me why it's not done yet, maybe i'm overseeing something?

cheers.