Sending Outlook emails to an iPhone user

I use Outlook on my laptop for personal use.  I have 4 email contacts that have iPhones. They have all complained that my emails TO them appear on their phones in script. My setting is HTML, with Comic Sans Serif, 14.  If I change the setting to Plain text, the emails are not in script, but then I have no emjois, spell check etc.  Is this an Apple/iPhone issue, or is there some way that I can just change my iPhone contacts to plain text?