If you're using Outlook Express, this can be very frustrating. No matter
what text size you have defined in OE, what gets printed will be different
(in my case, much larger than what I have specified). You have to choose a
reduced setting for View | Text Size in Internet Explorer, and there's a
limit on how low you can go this way.

If you're printing from within Word (used as your email editor), it may be
possible to use the Print Zoom feature in Word's Print dialog; since I don't
use Word as my email editor, I'm not familiar with how this works.