What is VMC, and do I need it?

Yes. In order to use BIMI, domain owners must have a verified email certificate (VMC) for their domain. A VMC is a special type of certificate that is issued by a trusted certificate authority (CA) - Currently being DigiCert and Entrust. It verifies that the domain owner is authorized to use the logo and provides a way for email receivers such as Google & Verizon to trust the messages that are sent from that domain. Without a VMC, BIMI would not be able to function fully, and email receivers would not be able to display the BIMI logo in messages.