randmap() lookup with percentage

[Tom Sommer]

I have a feature request for a lookup table like randmap(), but with the 
option to control a percentage or a count of mails sent to the 
transport.

Even if the percentage was just a "chance" of selection, it would be 
nice.

So you could do :

sender_dependent_default_transport_maps = randmap:{smtp1=90%,smtp2=10%}

Or is there another way to achieve this?

Thank you

--
Tom