How can I change the font and appearance of the email that goes with an estimate?

Hello Janeburton, 

Welcome to the Community page, 

If you click on the main cogwheel top right hand corner> then click on custom form styles> click on the estimate template if you have once on the list if not click new style top right and click on estimate> once it is open click on design> click on select a different font> then click the drop down arrow and choose a font and you can change the size as well> once all selected then click on done.