We continue evaluating several alternatives to provide full email customization. We are actively working on an alternative.
Unfortunately we do no yet have an ETA.
Thank you for your patience. We have released custom domains for Azure AD B2C to public preview.
Documentation can be found here: https://docs.microsoft.com/en-us/azure/active-directory-b2c/custom-domain?pivots=b2c-custom-policy
An error occurred while saving the commentSeamus Walsh commented
Is this feature still being considered?