I named my server hostname.local instead of hostname.com. Does that mean people can't send me mail at firstname.lastname@example.org?
Isn't there some setting where I can change the name that the server answers e-mail to?
The address does not have to be valid outside the organization. Define the valid address an inbound SMTP domain in each Internet mail service's routing property tab, then define how the messages would be handled -- such as inbound for local recipients or forwarded to other hosts. You may also use Recipient policies to define inbound SMTP domains (Exchange System Manager -> Recipients -> Recipients Policies container).