Hi Franchise Advisor,
Please find the below given instructions to change the font size on your email account
1. Log in to your Hotmail account with your MSN email id
2. At the upper-right corner of the page, click Options and then select More options on the dropdown menu.
3. Under Writing email, click Message font and signature
4. Select the Font and size which you prefer
5. Click Save.
Please reply for further assistance.
Thanks!