We're having issues with DKIM authentication. We have entered two addresses of our domain from which to send messages from Zoho Desk and we have the following problems:

1- The first address sent e-mail without problem, the second (most important) returns with the error: "Error while processing the request! Email Address should be verified to enable sending from this account. Provide confirmation code in Send Mail as section or POP Accounts section to verify." The domain is the same!

2- In DKIM Authentication we haven't our personalized domain.

Our email provider is Microsoft and our infrastructure is hybrid (AD+Azure)