Sending newsletter emails from custom domains account

we are using Microsoft's custom domains on our own domain. We have around 20 mail boxes there and we want to start sending automatic newsletter emails from an application using our special email account on custom domains. Mostly on emails under the same domain. I have found that after a while, account verification is required to send more emails - but that is a problem - because the sender is an application not a human. Currently it is working perfectly with a Gmail account. But we want to have it done by our email on the same domain as other user's emails. Is there such solution to turn the automatic verification off?