Open Outlook and click on File – Options – Mail – Stationery and Fonts
It will open up Signatures and Stationary dialog, switch to Personal Stationary tab to change default font settings for; New mail messages, Replying or forwarding messages, and Composing and reading plain text message. Here you can also change the generic Theme.
Change Default font styles & settings
For changing default font size, color and family, under New mail message section, click Font.
You will reach Font main dialog, start changing basic font settings; from Font select the font family, under Font style, choose desired style and from Size change the size of font.
Apart from the basic settings, you can also set some extra font settings such as; Font color, Underline Style and Color. From Effects, enable different font effects options. You can see all the changes in Preview pane. Once done, click OK to continue.
Repeat the same procedure for changing font settings for forwarding messages, by clicking Font button, under Replying or forwarding messages section.
Now on opening Mail Compose window, you will see changed default settings, i.e, font family, size, and color.
