[sylpheed:37145] Suppressing X-Mailer

Greatings!

I apologize if this has been asked before, but does anyone here know of a hack to completely suppress the 'X-Mailer' header on outdoing mail, the way Claws Mail does.

What I managed to acomplish so far is make it send an empty entry but can't figure out how to disable the header altogether.

Any sugestion would be much appreciated.

Thanks,