A test notification arriving in an inbox establishes that a delivery path worked at that moment. It does not, by itself, show that the selected rule includes a failed backup or another event the business needs to hear about. Review the rule and recipient together.

Start from the event and the responsible person

Choose one concrete operational concern, such as a backup failure. Identify who will act on it and where that person expects to receive the message. Avoid an old shared mailbox whose ownership is uncertain. Record the NAS identity and notification purpose so alerts from several devices remain distinguishable.

In DSM's notification settings, inspect the rule attached to the relevant delivery channel or email recipient profile. Synology provides default All, Warning and Critical rules and allows custom event selections. Read the included events instead of inferring them from a friendly rule name. A custom rule can remain named Backup alerts after its selections have changed.

Test delivery and event coverage separately

With the recipients' agreement, use the channel's documented test function and confirm actual receipt at the intended destination. Record the time, recipient and NAS identity. Check filtering or junk handling if the message is missing; a successful button press is not the same observation as receipt.

Then verify that the required event is included in the assigned rule. A delivery test should not be used to manufacture a real storage failure. Where a harmless planned operation generates an appropriate notification, compare the resulting message with the event and timing recorded in DSM.

Keep the recipient responsible for routine review even when notifications work. Staff changes, mailbox rules and channel settings can alter the route later. A useful handover names the event coverage, destination and person who will respond, plus the date of the last observed test. That makes a quiet inbox interpretable: it may mean no selected event occurred, not that the NAS has independently proved every backup and drive healthy.

Sources: Synology documentation 1, Synology documentation 2.