Quick Setup Checklist
Use this checklist to quickly locate the error source and collect the right logs before changing configuration.
Start with Logs and Channel Identification
Delivery failures can occur for different reasons depending on the channel, provider, or configuration.
When troubleshooting delivery errors, always start by:
- Checking message logs
- Identifying the channel used
- Reviewing provider-specific error details
Troubleshoot Twilio Channel Delivery Failures
If you are using a Twilio channel and messages fail to deliver, the issue is often related to channel configuration or provider restrictions.
In most cases, Twilio delivery failures occur because a trial number is connected. Trial numbers cannot send or receive real messages. A purchased Twilio number must be connected to send SMS to real contacts.
Open the Twilio channel settings
- Navigate to Settings
- Click on your Twilio channel
[CAPTURE: Settings page with a Twilio channel listed, and the channel selected.]
View recent errors or logs
In the Twilio channel view:
- Click the number listed under Recent Errors, or
- Open the channel logs to view sending activity
[CAPTURE: Twilio channel page with Recent Errors visible and a phone number listed.]
Review the sending log
The sending log shows:
- Message attempts
- Whether messages failed or succeeded
- Error details returned by Twilio
In many cases, the log will indicate that a trial number attempted to send messages to an unverified contact.
[CAPTURE: Twilio sending log highlighting a failed message due to a trial number.]
Important: Use the sending log to isolate the issue before making configuration changes.
Review Failed Messages Across All Channels
Delivery failures may also occur on non-Twilio channels due to provider-specific constraints or message routing issues.
Open the Failed messages folder
- Navigate to the Messages tab
- Select the Failed folder
[CAPTURE: Messages page with the Failed folder selected and failed messages listed.]
Open the message log
Click the red document icon next to a failed message. Depending on the channel, this will open:
- The channel error description, or
- The contact profile associated with the failed message
[CAPTURE: Failed message with the red document icon visible on the right.]
Important: When contacting support, always include a link to the error or a link to the contact profile.
Check Flow Results for Flow-Related Sending Issues
If messages are not sending because a flow is not behaving as expected, review recent flow runs.
Open flow results
- Navigate to the Flows section
- Open the affected flow
- Click the ☰ menu icon
- Select Results
[CAPTURE: Flow editor with the ☰ menu expanded and Results selected.]
Review recent runs
The Results view shows:
- Recent contact runs
- Where contacts entered or exited the flow
- Whether message actions were reached
Tip: If a contact never reached a Send Message action, no message would have been sent—even if the flow is active.
What to Include When Contacting Support
Providing direct links significantly speeds up investigation and resolution.
When requesting support for delivery failures, include:
- A direct link to the error (channel error / message log), or
- A link to the affected contact’s profile
- The channel/provider in use (e.g., Twilio, Android Relayer)
- The approximate time the message failed (and the contact’s timezone if relevant)
Common Issues
Messages fail on Twilio even though the flow ran
Possible causes: Trial number connected, unverified recipient (trial), or channel restrictions.
Fix: Confirm a purchased Twilio number is connected and review the Twilio sending log for the exact error message.
Messages fail due to invalid phone number formatting
Cause: The contact’s phone number is missing a country code or is not in the correct format.
Fix: Normalize phone numbers (E164 format) and retry sending.
Carrier filtering or blocking prevents delivery
Cause: Carriers may block content, sender IDs, or high-volume traffic that appears suspicious.
Fix: Review the provider error details, adjust message content if needed, and confirm compliance/opt-in practices.
The message shows as failed but I don’t see the error details
Possible cause: You are not opening the message log view.
Fix: Go to Messages → Failed and click the red document icon to open the error log or related contact record.
A flow is active but contacts never receive messages
Cause: The flow logic may not be reaching the message action node.
Fix: Use Flows → (flow) → ☰ → Results to confirm whether contacts reached the Send Message action.