Issue Summary

For some sites, some emails do not receive an email sent via Automation.

Steps to Reproduce

1. In automation, add an action to send an email to an email address owned by a user with no site access.
2. In the recipients, add an email of a user in all lower case, and add the same email with mixed upper and lower case.
3. Trigger the automation.

Expected Results

• The automation would send the email to the all lowercase as well as mixed upper and lowercase email address.

Actual Results

• Email is only sent to the mail with mixed upper and lower case email address with the message in the audit log.

  We couldn't send emails to some recipients. This may be for data privacy or recipient email account configuration reasons. Check the action and try again, or contact Atlassian support.
  If your organization has policies such as filter content or external user security (EUS), emails from this action may not be sent to some recipients. Contact your site admin or support if emails were not received.
  

Workaround

• Use the mixed upper and lower case of the email address as the recipient.