Contoso uses contoso.com for email and wants a second accepted domain partners.contoso.com for a partner-facing mail namespace. After adding/verifying the domain, what else is typically required for mail?
Select an answer to reveal the explanation.
Short Explanation and Infographic
Second domain = verify + DNS + tell Exchange it's accepted mail. Skipping DNS is how mail vanishes into the void.
Full explanation below image
Full Explanation
Correct Answer — B
Additional domains require verification and DNS for mail/auth scenarios, plus configuration so Exchange Online treats the domain as accepted for recipients.
Why A is wrong: DNS is required for mail.
Why C is wrong: Disabling existing domains breaks production identities.
Why D is wrong: Removes identity platform.
Exam tip: New mail domain → verify + MX/SPF + accepted domain.