Two connections shared by ports

[Tony VanScoy]

My Goal:  Setup ipfilter to share two Internet connections.

Perhaps sharing is the wrong word.  I would like ipfilters to use 
Internet connection 1 for any  traffic, incoming and outgoing, through 
ports 21,25, 110, 143, 995, and maybe others.  The rest of the traffic 
would travel through Internet connection 2 without limits.

The problem is that our office uploads numerous files through mail and 
ftp that are usually 50M, possibly larger.  These uploads are unmanaged 
and suck the life out of our bandwidth.  It sucks browsing the net like 
I was back on my 28.8 dial up. I just want to dedicate one of our 
connections for those uploads/downloads to relieve the office of these 
troubles.

Is it possible?