Hello Mukesh Kumar, for Publisher Verification, the user signing up for the Partner Center account does not necessarily need mailbox access with the custom domain email address. However, the email address used during the verification process must match the custom domain verified in your Entra tenant. Regarding the custom domain, it needs to be DNS-verified custom domain added to your Entra tenant. This means the domain must be verified within your Entra tenant, but it does not need to be linked to a specific mail provider.
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