Oh, I think I see what you are asking. Are you concerned because you'll have a company web site at "mycompany.com" on one server, and your email "xxxxx@mycompany.com" on a different server?
That's no problem at all. That's what "A" records and "MX" records on your public DNS server are for. The MX (mail exchanger) record tells where the mail server is located, which can be a completely different location than the company's web site.