Change e-mail font size, color, style

I have read numerous suggestions in this forum and elsewhere online. I have not been successful in choosing the font size, color, or style for my Mac e-mails. What is available is not satisfactory for my eyesight. I do not want to go through the "magnify" process each time I want to use the e-mail tool.

G'day and welcome to the forums.

Helps if you provide operating system details as they can vary from version to version. However go into Mail Preferences > Fonts & Colours and there set the font size and colours to your satisfaction.