I just started at my company and trying to understand the following:
Our internal domain is: domain.company.com but our email address for our company is mail.company.com
Under ADUC, there is not an option for additional DNS suffixed for UPN login. With this in mind, how is it that users are able to log into the domain using there email address?
Nothing is listed under AD Domain and Trust as well...
There is no parent company.