Undeliverable emails in sys_email in UAT instance

[SaiMounikaY]

configured the notifications with who to send list configured. we are receiving the notifications hwne the record is inserted or triggered to who to send receipient list after that we are getting same emails generated with random UAT mail address as subject undeliverable and when i open that and preview the emial i am getting below error:

hr_test_uat@mailadress.com

The recipient's mailbox is full and can't accept messages now.

554 5.2.2 mailbox full.
How caj i fix the issue

[kmohammed]

Hi,

This is not a ServiceNow sending error - it is a bounce coming back from the recipient's mail server, and the clue is in the error itself:

554 5.2.2 mailbox full - The recipient's mailbox is full and can't accept messages now.

What is happening:

1. Your original notification IS being sent correctly - that is why the intended recipients receive it.

2. One address in the recipient list, hr_test_uat@mailadress.com, has a full mailbox (quota exceeded) on the mail server.

3. That mail server rejects the message and sends a delivery failure (bounce) message back to the instance. ServiceNow records that incoming bounce in sys_email as a separate received email with subject Undeliverable - it did not generate a second, duplicate notification.

How to fix it - the fix is on the mailbox/recipient side, not in sys_email and not in the notification:

- Ask your mail team to clear or increase the quota on that test mailbox (test/UAT mailboxes fill up exactly this way, because nobody empties them), OR

- Remove/replace that address everywhere it is being picked up: check the notification's Who will receive list, and also the user/group it may come from (a user record or group email field still carrying that UAT address, or a recipient copied from a user/group on the record that triggered the notification). Search users and groups for that exact email address.

Two UAT-specific points:

- Do not edit or delete the Undeliverable sys_email records to fix this - they are only the record of the bounce. Deleting them just hides the symptom and a new one will arrive with the next notification to that address.

- If UAT should not be mailing real mailboxes at all, use Email Properties in the sub-production instance to redirect all outbound mail to a single test address (or disable outbound email there), rather than maintaining real recipient lists in UAT.

Verify: trigger one record after the mailbox is cleared / the address is removed, then check sys_email - the outbound notification should show as sent/processed and no new Undeliverable bounce should come back.