# 30453: Message couldn't be delivered

Log Type: APPLICATION

Log Level: ERROR

## Description

Twilio temporarily blocked delivery to this destination because SMS Pumping Protection flagged traffic to the number as suspicious. This block usually clears after a few hours if no additional fraudulent activity is detected.

### Possible causes

* SMS Pumping Protection detected unusual traffic patterns for this destination or matched the traffic to system-known malicious activity.
* Twilio temporarily blocked SMS traffic to the destination number while the fraud check remained active.
* A legitimate recipient was flagged by mistake. False positives are possible, although Twilio works to keep them low.

### Possible solutions

* Wait a few hours and try the message again. In many cases, the block is temporary and clears if Twilio does not detect additional suspicious activity.
* If the traffic is legitimate and the issue continues, collect at least three affected Message SIDs from the last 24 hours in your SMS logs and open a support request for investigation.
* If you need to send a known legitimate message without applying this risk check, set `RiskCheck` to `disable` when you create the Message resource.
* Add trusted destination phone numbers or eligible 1k prefixes to the Global Safe List so they are not blocked by SMS Pumping Protection in the future.

#### Additional resources

* [SMS Pumping Protection for Programmable Messaging](/docs/messaging/features/sms-pumping-protection-programmable-messaging)
* [Create a Message resource](/docs/messaging/api/message-resource#create-a-message-resource)
* [Global Safe List](/docs/usage/global-safe-list)