Don't see why not! I install and run Office 95 on an XP PC with no issue; about the same gap.
Office usually offers you a choice of which components you want to install. If so, you can just install Outlook which would not clash with anything already there.
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 19 Meg WBC