How do I add my email icon on my iPhone start page?

Thank you for reaching out. At Apple, quality is a top priority. Regarding your question, your email icon should be on your home page by default. It is possible you may have deleted it during the set up of your iPhone. If you can no longer find you email application, go to the App Store on your iPhone and search for "Mail". You should see a blue icon with an envelope on it called Mail. This is iPhones default mailing app. Click install or the download icon on the app page. Then you can rearrange the app as you wish.