Whenever I use a multiple column responsive layout, Outlook 2007/2010 seems to need more space.

For example, if I have 4 columns each at 25%, in other clients all 4 columns fit = 100% but in Outlook 07/10 only 3 columns will fit.

Even with fixed widths, Outlook seems to put a space between each column:
actual

When in other clients it looks like this (the way I want it to):
expected

Anyone know how I can fix this?