The check for unsupported events types happens before any destination filter checks. As a result, Destination Filters can't prevent unsupported event type errors. To filter these events, use the[Integrations Object](/docs/guides/filtering-data/#filtering-with-the-integrations-object).

If Event Delivery page shows events have been retried, the retries could account for events that did not get filtered when the Destination Filter is just added. Such scenario can occur when an event was sent to the destination and encountered timeout error, and retries for the events are attempted. While the retries are attempted, and a Destination Filter is then added, these retries will not subject to the filtering since these are from the events sent before the Destination Filter is added.

Destination filters only filter events sent after filter setup. If you just added a destination filter but still see some events going through, you're likely seeing retries from failed events that occurred before you set up the filter.

When Segment sends an event to a destination but encounters a timeout error, it attempts to send the event again. As a result, if you add a destination filter while Segment is trying to send a failed event, these retries could filter through, since they reflect events that occurred before filter setup.