Receiving emails or business emails with @gmail.com or @yahoo.com does not view the company with the same identity as using their website domain in the email. An impression of a firm identity is a must in a business.

Suppose if you give two choices. One with @gmail or @yahoo.com business email. And another with your own website domain in the email like erik@xyz.com. Where Erik is the employee name and xyz is the company name(for example only). Although, personal or business emails do a similar job people would choose the latter one because it sounds genuine.