It's frustrating when a text message never arrives—whether it's a tour reminder, an enrollment update, or a reply to a parent. This guide walks you through each step of the delivery process, shows you where things can go wrong, and gives you clear fixes so you can get back on track fast.
How Message Delivery Works
When you send a text from Enrollio, it travels through multiple layers:
- Enrollio Platform Layer — We check your account status, message limits, and contact preferences
- Twilio Layer — Our messaging provider queues and routes your message
- Carrier Network Layer — The parent's mobile carrier delivers the message to their phone
If the message fails at any layer, it won't be delivered. Let's look at how to spot these issues and fix them.
[SCREENSHOT: Diagram showing the three layers of message delivery from Enrollio to parent's phone]Where to Find Error Messages in Enrollio
If your message didn't go through, check the Conversations view. When a message fails to send or deliver, we display an error directly in the conversation thread.
The error message and error code give you clues about what went wrong and how to fix it.
[SCREENSHOT: Conversations view showing a failed message with red error badge and error code displayed]Common Reasons Why Messages Fail (And How to Fix Them)
1. At the Enrollio Platform Layer
| Issue | Cause | Fix |
|---|---|---|
| Contact has Do Not Disturb (DND) enabled | When DND is enabled for a parent on the message channel, Enrollio won't send the message and displays an error in the conversation screen. | Remove DND status from the parent's contact record to resume messaging. Go to the parent's profile → Communication Settings → Remove DND. |
| The Number Is a Landline | When number validation is enabled, Enrollio checks if a number can receive text messages. Landlines can't receive texts. | Use a mobile number instead. If you need to disable number validation for special cases, contact support. |
| New Account Undergoing Ramped Sending | Enrollio restricts message volume for new accounts to prevent spam, gradually increasing limits over your first few weeks. | Wait for limits to increase automatically as you build sending history. Contact support if you need an emergency increase. |
| Daily Message Limit Reached | Each account has a daily message limit. Bulk and automated messages stop sending once this limit is hit, but individual replies can still be sent. | Wait until the next day when limits reset, or contact Enrollio to request a limit increase if your center has grown. |
| Sending Suspended Due to High Errors or Complaints | Accounts exceeding spam, opt-out, or carrier complaint thresholds have message sending temporarily suspended. | Review your messaging practices and ensure you're only texting families who opted in. Contact support to resolve the suspension and review your account standing. |
2. At the Twilio Messaging Layer
| Error | Cause | Fix |
|---|---|---|
| Number is on Twilio's DND list | The number is on Twilio's Do Not Disturb list due to a previous opt-out or carrier complaint. Messages will fail unless the contact opts back in. | The parent must text "START" to your Enrollio number to re-enable messaging. |
| 30001: Queue Overflow | Messages are queued based on sending rates. If they stay in the queue for over 4 hours, they automatically fail. | This typically happens with very old queued messages. Contact support if you see this error frequently. |
| 30002: Suspended Account | The message fails if your messaging account is suspended between queuing and sending. | Contact Enrollio support immediately to resolve the suspension. |
3. At the Carrier Network Layer
| Error | Cause | Fix |
|---|---|---|
| 30003: Unreachable Destination | The parent's phone may be off, have no signal, be a landline, or there may be a mobile carrier issue. | Retry later or verify the number is a mobile line. Ask the parent to confirm their number is correct. |
| 30004: Message Blocked | The number is blocked, the device can't receive messages, the number is on a Do Not Call registry, there's a carrier issue, or the number previously opted out. | Ensure the number is valid and opted in. Ask the parent to text "START" to your number if they want to receive messages. |
| Attachment File Too Large | The file size exceeds carrier limits for MMS (typically 5MB). | Compress images before sending or use a file-sharing link for larger documents. Keep attachments under 1MB for best delivery. |
| International Geo Permissions | Your account might not have permission to send international messages. | Contact Enrollio support if you need to send messages to international numbers. |
| Message Body Too Long | The message exceeds carrier character limits (1,600 characters). This can happen if you're using custom values that pull in long text. | Trim the message manually or modify your automation to exclude large custom values. Keep messages under 300 characters for best results. |
Pro Tip: Most text message failures happen because a parent changed their number or their phone is off. Before troubleshooting technical issues, try calling the number to verify it's still active.
Quick Checklist Before You Click "Send"
- Check Conversations: Look for any red error badge on previous messages
- Match Error Code: Use the tables above to find the cause
- Apply Fix: Follow the "Fix" column for that issue
- Retry: Resend the message after making adjustments
- Monitor: Confirm delivery or note any new error code
Frequently Asked Questions
Why am I getting charged for failed messages?
Charges apply once a message is attempted—even if it fails later in the delivery process. This is because the message still consumes resources as it moves through the delivery pipeline.
How do I know exactly why a message failed?
Check the error code displayed in the Conversations view. Each error code corresponds to a specific issue in the tables above. If you need more detailed technical logs, contact Enrollio support.
What's the difference between "Sent" and "Delivered"?
"Sent" means Enrollio successfully handed the message to the carrier network. "Delivered" means the carrier confirmed the message reached the parent's phone. A message can be "Sent" but never "Delivered" if the phone is off or out of range.
Can I prevent messages from being sent to landlines?
Yes, number validation is typically enabled by default in Enrollio. This checks if a number can receive texts before sending. If you're still seeing landline issues, contact support to verify your validation settings.
A parent says they never received my message, but I don't see any error. What happened?
Sometimes carrier filtering can silently block messages without sending an error code back to us. This is most common when sending the same message to many recipients at once. Ask the parent to check their spam/blocked messages folder, and consider rephrasing your message to be more personalized.