Sometimes, messages sent through SchoolStatus Connect may fail to reach a user by email or SMS. When this happens, we display technical details in the user’s profile to help you understand what went wrong. This article explains how to interpret those details and what steps you can take.
How to locate the Delivery Failure codes in Connect?
Navigate to the Directory tab.
Click on Filters.
Under the Communications section, select Unreachable.
You will see a red exclamation icon next to the unreachable users.
Click on the user/warning icon to display the user profile.
Next to the contact method, click the arrow to expand and locate the “error code” for the phone number, or “reason” for an email address.
1. For SMS Delivery Failures: Understanding Error Codes
When an SMS fails to deliver, the error message from the carrier can be technical and difficult to read. Instead of trying to decipher the entire message, look for a specific error_code within it. This code is the key to understanding the problem.
Below is a list of some common error codes and what they typically mean:
| Error Code | Reason | Description |
20 | Network Error | The carrier delivering the text message had network issues. This is a temporary error. |
30 | Spam Detected | SMS delivery failures often occur due to carrier-level spam filters, which block messages based on hidden and constantly changing rules. |
40 | Invalid Source Number | The source number is either incorrectly formatted or not SMS-enabled. |
50 | Invalid Destination Number | The destination number is either entered incorrectly, not SMS-enabled, or is a PSTN landline. |
70 | Destination Permanently Unavailable | The phone number you’re trying to reach appears to be inactive, and the carrier hasn’t shared a specific reason. Double-check that the number is correct. If possible, try reaching the user at a different number to make sure your messages are sending properly. |
80 | Destination Temporarily Unavailable | The destination (“dst”) phone number can’t be reached. This usually means the phone is turned off or out of coverage. Try resending the message later. |
90 | No Route Available | The carrier and fallback carriers were not able to deliver the SMS message because no route was available. Carriers don’t provide a reason why a route is unavailable, but this is typically a carrier issue. |
100 | Prohibited by Carrier | The carrier rejected the message because the network doesn’t support the message being sent. This can occur if the destination network doesn’t support SMS. |
200 | Source Number Blocked by STOP from Destination Number | The destination has opted out of the campaign and blocked all messages from the sending phone number. All messages to destinations that have opted out are blocked until the destination opts in with another response. |
30003 | Message Delivery - Unreachable destination handset | The message failed due to an unavailable or unreachable destination. Common examples are a user who is outside of cellular service or whose mobile device is powered off. |
30005 | Message Delivery - Unknown destination handset | The delivery of your message failed due to an unknown or inactive destination number, for example a number that is no longer in service. |
30006 | Message Delivery - Landline or unreachable carrier | The message delivery failed due to the destination being a landline and incapable of receiving SMS, or an unreachable destination carrier. |
"nil" or "null" | The delivery status is unknown or undefined | The service that sends your text messages didn’t get confirmation from the mobile carrier that the message was delivered. This can be treated as a "no-receipt, no-acknowledgment" status and is different from a specific failure code, like "invalid number" or "phone busy." |
⚠️ If you see an error code not listed here, it may indicate other temporary or permanent delivery issues.
Recommendations for common error codes:
Temporary Errors
If the error appears to be a temporary delivery issue, use Reset Bad Credential. This allows the system to attempt sending new communications to that credential again.
💡Note: Resetting a bad status won’t resend past messages; it simply clears the error, and you’ll need to send a new message to test if the contact can receive signals.
Permanent Errors
If the error looks permanent, first double-check the destination phone number for accuracy. If the number is correct, consider reaching out to the user to confirm if it’s still their active phone number. If confirmed, the user may need to contact their mobile carrier to determine why they are unable to receive messages from SchoolStatus.
2. For Email Delivery Failures: Understanding Error Codes
Email delivery failures are usually more straightforward, as the error message often clearly states the reason for the failure.
| Reason/Error | Description | Action |
| “User Unknown”, “Invalid Address”, "User does not exist", or "Mailbox not found" | The email address does not exist. | Please check for typos, contact the user, and see if it is their actual email address. |
| “Mailbox Full”, "User is over quota" | The recipient's inbox is full and cannot accept new messages. | Ask the user to clear space in their mailbox. |
| “Message Blocked” or “Rejected by Filter” | The receiving mail server has classified our message as spam or has a rule blocking it. | Ask the user to whitelist emails from the SchoolStatus domain or check their spam filter settings. |
| “Server not responding” | A temporary issue with the recipient's email provider. | Try resetting the Contact method Status so that the system tries to send the new messages to the user. |
| "Requested action not taken: Mailbox Unavailable" | Common reasons include an invalid email address, a full or offline mailbox, a disabled account, or the message being blocked by the recipient’s server. | Confirm the user's email address, Contact the receipient to verify their email account status, and make another attempt. |
| "Bounced Address" | Hard Bounce could be due to: invalid address, inactive/misconfigured server, or recepient blocked sender's IP. Soft Bounce may happen when the recepient mailbox is full, server is temporarily down, or a spam filter was triggered. | Look for the bounce-back message or error code to understand the reason for the failure |
| "Timeout" | When an email is sent, the mail server will only wait a set amount of time for a response from the other server before giving up. | Check internet connection, Verify server details, Send test email, or Contact email provider. |
⚠️ For some older accounts or in rare cases, you might see a failure with no specific error code or reason. This could happen due to the historical data being incomplete. The best way to resolve this is to:
- Reset Contact Method & try Again: Use the Reset Status function (Click here to learn more about this feature)and attempt to send notifications again. The new attempt will generate a fresh, more detailed status.
- Verify Contact Information Directly: If possible, contact the user through an alternative method (e.g., a different email or phone number) to confirm their primary contact details are still correct.
- Contact Support: If the issue persists and you're unsure of the next steps, please contact our Support Team. Provide them with the user's profile information and the date/time of the failure, and we will be happy to investigate.
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