Technically speaking, we are hosting your website. Although since we don’t provide any hosting services such as email, we shouldn’t be viewed as a typical “hosting provider”. In this way (when you follow our instructions for how to set up a domain), you can “point” your custom domain (i.e. www.yourdomain.com) to IconoSites yet still have the ability to host your email with your hosting provider.
You DO NOT need to buy a hosting plan from your Domain Registrar (which is most likely also a hosting provider).
You only need to buy email support (most hosting providers charge for this separately) IF AND ONLY IF you plan to set up email addresses with your domain. If you don’t need to set up email addresses, then you don’t need to buy anything at all.