X-Mailer in addition to User-Agent?

[Kousik Nandy]

Hi,
        If we have pref("mailnews.headers.showUserAgent",true)
then we get to see the User-Agent in the headers. Now, there are
several mail clients (except our Mozilla, mutt to name a few)
use X-Mailer to identify themselves. Can't this happen that when
showUserAgent is true, then mozilla shows User-Agent or X-Mailer
whichever is available?

Thanks
Kousik.