Even with a verified domain, when customers want Jira to send emails on their behalf, it's necessary to add the domain at:

• From your organization at admin.atlassian.com, select Settings > Emails.
• If you already have domains, you’ll see two tabs. Select Email domains.
• Select the Add domain button.
• From the Add email domain modal, enter your company’s domain and click Add.

There's a daily validation on all DNS records. If customers use the cname flatenning feature it will hide the cname entry on the DNS, and the validation will fail on the Atlassian side.

Make it possible to validate the DNS records even when using cname flatenning.