1 Answer

Instructions
Change Font Size in a Yahoo! Mail Message

1
Click "New" to compose a message and click "Rich Text" beside the "Subject" line to show font options. The appearance bar will open in your e-mail message; you can change font color and size here.

2
Highlight the text you want to change the font size.

3

Look to the font options toolbar above the e-mail message and click the arrow beside "12," the default font size. A drop-down list will open with the available font sizes.

4
Select a different font size from the drop-down list. The font size of the selected text will change.

Change Font Size Permanently in Yahoo! Mail

5
Sign in to your Yahoo! Mail account and click "Options" located at the top, right corner of the window.

6
Select "More Options" from the drop-down list. The Options page will open. You can change your signature or message settings here.

7
Select "General" from the list of options and look to the section marked "Plain text font."

8
Click the arrow beside "12," the default font size and select a different font size from the drop-down list.

9
Click "Save Changes" to save the new font size.

Read more: http://www.ehow.com/how_7246824_change-font-size-yahoo.html#ixzz2cwJGqP6v