Setting up delivery notifications
You can set up delivery report notifications to be alerted when messages are delivered or fail. These notifications can be sent via email. Messages can sometimes appear as "Sent" or "Delivered" but still not be received by the recipient. Understanding why this happens is crucial for troubleshooting delivery issues.
However, if you’re using the email option, it is recommended to select Only on Failure to avoid receiving an email for every message sent.
Common Reasons for SMS Delivery Issues
1. Delayed Delivery
After sending an SMS through ClickSend, the message is forwarded to mobile networks almost instantly. However, delivery can be delayed due to carrier or mobile network-related factors on the recipient’s side, such as temporary network congestion or delays.
2. "Sent" Status but Not Received
The "Sent" status indicates that ClickSend successfully handed the message off to the carrier. However, delivery to the handset depends on factors outside ClickSend’s control, such as:
Recipient device being off or out of coverage
Full SMS inbox
Carrier filtering or plan issues
Network delays
3. "Delivered" Status but Not Found
A message marked as "Delivered" means it reached the carrier network and, based on logs, the recipient handset. However, recipients may still not see it due to:
No signal or temporary network issues
Device turned off
Full SMS inbox
Carrier delays in presenting the message on the device
Timing of delivery notifications
The timing of delivery notifications will depend on the networks. But here are some timings you can expect:
Notifications for failed messages due to account issues are typically sent instantly.
Notifications for messages delayed due to the recipient’s phone being turned off may take up to 72 hours, as networks attempt to deliver the message multiple times before marking it as failed. - Delivery delays can also occur due to carrier or network congestion on the recipient's side.
Messages may fail to deliver if the recipient's SMS inbox is full or if carrier filtering blocks the message.
Troubleshooting delivery failures
Before reporting a delivery issue to our team, try these common troubleshooting steps to identify the problem.
Check your setup
Test SMS replies: Send an SMS to your own number and reply to it. This confirms if your inbound messages are working correctly.
Verify campaign details: If you are sending an SMS or MMS Campaign, ensure all required fields are filled. An empty campaign name can silently block your messages from sending.
Check account balance: Make sure you have sufficient funds before starting a campaign. Low balances can trigger automatic cancellations.
Try SMS instead of MMS: If timing is critical and MMS messages are delayed in a "WaitApproval" state, try sending a standard SMS instead.
Identify common causes
If your messages are failing (such as an "Unidentified Subscriber" error), it is usually due to one of these factors:
Recipient-side issues: The number is invalid, inactive, or a landline. Suggest the recipient check their spam folders or restart their device.
Carrier-side issues: Networks may block messages due to heavy congestion or strict anti-spam filters. Avoid prohibited words.
Virtual numbers: Some carriers block SMS traffic to virtual numbers for security reasons. Use a real mobile number or toll-free number for authentication flows and verification codes.
Region-specific requirements: Sending to the US and Canada requires a registered Toll-Free Number (TFN) or 10DLC number. Italian recipients require pre-registration of alpha tags. Review our Global Sending guidelines for specific regional rules.
If you are still experiencing issues after trying these steps, follow the instructions below to report it to our team.
How to report delivery issues
This unique message ID can be used to report delivery issues to the networks. To investigate undelivered SMS messages, ensure to provide fresh samples, ideally at least three examples of undelivered messages sent to different recipients within the last 24 hours. Fresh samples aid in accurate investigation results, although samples up to 48 hours may still be considered. Include message IDs and timestamps for each sample to assist in a more precise investigation.
You can report SMS delivery issues directly from your ClickSend account by following these steps:
Log in to your ClickSend dashboard.
Navigate to SMS History by clicking SMS in the left-side menu and selecting History.
Locate the specific message that was undelivered or failed delivery.
Hover over the message to reveal the Information (i) icon.
Click the Information (i) icon to access detailed options for the message.
Scroll to the bottom of the details page and click the Report button to submit your delivery issue. Providing necessary delivery samples as outlined will help the ClickSend team conduct an efficient investigation and resolve your problem.
The ClickSend support team will follow up with you via email once they receive information from the networks. It's highly recommended to report issues within 24 hours of sending the messages, as this significantly improves the chances of a successful investigation. Messages sent up to 48 hours prior may still be investigated, but prompt reporting is advised. Additionally, ensure that the recipient numbers are in full international format (E.164) to avoid formatting-related delivery issues.
Test your delivery reports are working
To ensure your delivery reporting is working correctly, follow these steps:
Go to Account Settings > Messaging Settings > Delivery Reports Rules.
Check the rules listed.
If you need to create a new rule, click the blue Add New Rule button.
Select report on failure or report on success.
Add your email and click Save.
Test the delivery function by sending a message to your number for a report on success or to a number with a non-existent prefix (e.g., 555) to test the failure report.