Email formatting

Email formatting

I am having problems with the standard formatting of emails which are sent from Zoho CRM. No matter what I do, the font reverts to a standard format of Times New Roman. If I create a template and send that then I have no problems but if I just send one email in an individual format it reverts to Times New Roman.
 
Is there anywhere where I can alter the standard formatting or is there something wrong in my settings?