I host my email with FastMail who allow the use of subdomains. This is a great feature, and I use it frequently. HOWEVER, you should only do so after careful c

I host my email with FastMail who allow the use of subdomains. This is a great feature, and I use it frequently. HOWEVER, you should only do so after careful consideration. This will restrict moving your email hosting to the limited number of providers who provide provide this type of service, or hosting your own server. Alternatively, you could go and reset your email address with all of the services that you gave a subdomain email. For myself, I have been using FastMail for years and feel confident that I will continue to use their services. In the event that I needed to move from FastMail, I know that could self host if forced to.