Email to Verify changed email address is not delivered

[Admin Ans - Test]

Before configuring SAML SSO, Atlassian recommends to create an Atlassian Site&Org admin account with an email address outside the managed domain.
Our current admin accounts are within the managed domain, so we need to change their email addresses.
In a Test Jira environment with verified domain "company.com" an existing admin user was renamed in the Org directory from "admin@company.com" to "admin@company.onmicrosoft.com".
Both email addresses are aliases of the same M365 user account. Emails sent from any mailbox to both these email addresses are correctly received. But after changing the email address in the Atlassian Org Directory:
- The email from Atlassian "Email address change request" is correctly delivered to the old email address "admin@company.com".
- But the email from Atlassian "Please verify your email address" is not delivered to the new email address "admin@company.onmicrosoft.com". Not in the Inbox, not in the Spam/Junk folder, nowhere.

What can be the cause that this email from Atlassian is not delivered?

[Angélica Luz]

Hello @Admin Ans - Test,

Welcome to Atlassian Community!

Checking the domains from the users of your site, some of them had bounces due to the following error:

550: 550 5.4.1 Recipient address rejected: Access denied. AS({hex}) [AM6EUR05FT047.eop-eur05.prod.protection.outlook.com]

The admin account was not included on the affected addresses, but I removed the bounces for the notifications to work.

If you still don't receive the notification, please, whitelist our domains and IPs to make sure the notifications and the products work as expected:

• Atlassian cloud IP ranges and domains

Regards,
Angélica

[Prince Nyeche]

Hi @Admin Ans - Test 

Yes the reason for that is not to be locked out of your Admin hub due to failed configuration. if the mail is not be delivered. please reach out to Atlassian support to help confirm if the address is not being blocked by their systems. However ensure that you're on at least a Standard Plan and not a free plan to get support assistance.