In my experience, having an email address ending with any custom domain other than "gmail.com" raises questions and clarifications are necessary quite often.
And I always think: "you went to the effort to get a domain name and put a website up, but you couldn't go the one more step and have your email point there too?" Especially since you likely hired a web company to do the website, why didn't they also do the email? At least in these cases a company's web-savvyness (or grammar) don't necessarily affect their building skill.
Because nobody knows why "business1@gmail.com" and "business2@gmail.com" are actually different businesses, but "business1@stavros.com" and "business2@stavros.com" aren't. Who knows if your domain is a mail provider or not, or what a domain is, or how mail servers work, etc etc.
People have no idea how email works (and why should they?).