Introduction #
Delivery Reports (DLR) provide real-time status updates for your sent SMS messages. Understanding DLR helps you track message delivery, identify issues, and ensure your messages reach recipients successfully. This guide explains everything you need to know about DLR in the SMSGatewayCenter mobile app.
What is DLR? #
Delivery Report (DLR) is a confirmation message that tells you the delivery status of your sent SMS. It’s like a receipt that confirms whether your message was successfully delivered to the recipient’s device.
Why DLR Matters #
- ✅ Track Message Delivery: Know if your SMS reached the recipient
- ✅ Identify Issues: Quickly spot failed deliveries
- ✅ Improve Success Rate: Learn which numbers are invalid or inactive
- ✅ Accountability: Proof of delivery for business communications
DLR Status Types Explained #
1. Pending #
What it means: SMS is queued and waiting to be sent to the mobile network.
What to expect:
- Status appears immediately after sending
- Usually updates within a few seconds
- Normal part of the sending process
Action required: None – just wait for status update.
Typical duration: Few seconds to 1 minute
2. Sent #
What it means: SMS has been successfully sent to the mobile network operator (carrier).
What to expect:
- Status updates from “Pending” to “Sent”
- Message is now in the carrier’s network
- Waiting for delivery confirmation from recipient’s carrier
Action required: Wait for delivery confirmation.
Typical duration: 1-5 minutes before delivery confirmation
3. Delivered ✅ #
What it means: SMS has been successfully delivered to the recipient’s device.
What to expect:
- This is the desired status
- Message reached recipient’s phone
- Recipient can now read the message
Action required: None – message delivered successfully!
Typical duration: Usually within 1-5 minutes of “Sent” status
Note: Some carriers don’t send delivery confirmations, so “Sent” may be the final status in some cases.
4. Failed ❌ #
What it means: SMS could not be delivered to the recipient.
Common reasons:
- ❌ Invalid phone number: Number doesn’t exist or is incorrectly formatted
- ❌ Recipient’s phone is off: Device is powered off or out of coverage
- ❌ Network issues: Temporary carrier network problems
- ❌ Number blocked: Recipient has blocked SMS from your sender ID
- ❌ Inactive number: Phone number is no longer in service
- ❌ Carrier rejection: Mobile operator rejected the message
Action required:
- Verify recipient number format (should be international format)
- Check if number is active
- Try resending after some time
- Contact support if issue persists
Typical duration: Status updates within 1-10 minutes
5. Expired #
What it means: SMS delivery attempt expired after maximum retry period (usually 24-48 hours).
What to expect:
- Carrier tried to deliver but couldn’t reach recipient
- Maximum retry period has passed
- Message will not be delivered
Action required:
- Verify recipient number
- Resend message if needed
- Update contact if number is invalid
Typical duration: 24-48 hours after initial send attempt
How to View DLR Status #
Method 1: In Quick SMS Screen #
After sending an SMS:
- Status appears immediately below the sent message
- Status updates automatically (no refresh needed)
- Color coding helps identify status:
- 🟡 Pending: Yellow/Orange
- 🔵 Sent: Blue
- 🟢 Delivered: Green
- 🔴 Failed: Red
Method 2: In Reports/History Section #
- Navigate to “Reports” or “History” from main menu
- Find your sent message in the list
- Check the Status column
- Tap on message for detailed DLR information:
- Sent time
- Delivered time (if delivered)
- Delivery duration
- Error message (if failed)
Method 3: Real-Time Updates #
- DLR status updates automatically
- No need to manually refresh
- Push notifications may alert you of status changes
- Enable notifications: How to Enable/Disable Notifications
Understanding DLR Timestamps #
Each DLR includes important timing information:
Sent Time #
- What it is: When SMS left our gateway and was sent to carrier
- Where to find: Reports > Message Details > Sent Time
- Use case: Track when message was dispatched
Delivered Time #
- What it is: When SMS reached recipient’s device
- Where to find: Reports > Message Details > Delivered Time
- Use case: Confirm delivery and calculate delivery speed
Delivery Duration #
- What it is: Time difference between Sent and Delivered
- Calculation: Delivered Time – Sent Time
- Typical range: 30 seconds to 5 minutes (most common: 1-2 minutes)
Common DLR Scenarios #
Scenario 1: Immediate Delivery ✅ #
Timeline:
- 10:00:00 – SMS Sent
- 10:00:45 – SMS Delivered
What it means:
- Recipient’s phone is on and connected
- Good network conditions
- Valid, active phone number
Action: None needed – perfect delivery!
Scenario 2: Delayed Delivery ✅ #
Timeline:
- 10:00:00 – SMS Sent
- 10:15:30 – SMS Delivered (15 minutes later)
What it means:
- Recipient’s phone was off or out of coverage
- Phone came back online
- Message was queued and delivered when phone became available
Action: None needed – message was delivered successfully!
Scenario 3: Failed Delivery ❌ #
Timeline:
- 10:00:00 – SMS Sent
- 10:02:15 – Status: Failed
What it means:
- Cannot deliver to this number
- Possible reasons: Invalid number, phone off for extended period, carrier rejection
Action:
- Verify number format
- Check if number is active
- Try resending after some time
- Remove from contact list if repeatedly failing
Scenario 4: No Delivery Confirmation #
Timeline:
- 10:00:00 – SMS Sent
- Status remains “Sent” (never changes to “Delivered”)
What it means:
- Some carriers don’t send delivery confirmations
- Message may have been delivered, but no confirmation received
- Common in some regions or with certain carriers
Action:
- Assume message was delivered if status is “Sent” for extended period
- Check with recipient if delivery confirmation is critical
Tips for Better Delivery Rates #
1. Use Correct Number Format #
- ✅ Always use international format: +[country code][number]
- ✅ Example: +1234567890 (USA), +919876543210 (India)
- ❌ Don’t use: Local format without country code
- ❌ Don’t include: Spaces, dashes, parentheses
2. Verify Recipient Numbers #
- Double-check numbers before sending
- Remove invalid or inactive numbers from contact list
- Update contacts regularly
3. Send During Business Hours #
- Higher delivery rates during active hours (9 AM – 9 PM)
- Avoid sending to inactive numbers late at night
- Better network conditions during business hours
4. Monitor Failed Messages #
- Review failed DLRs regularly
- Identify patterns (certain numbers always fail)
- Update your contact list accordingly
- Remove consistently failing numbers
5. Check Account Balance #
- Low balance may cause delivery issues
- Ensure sufficient credits before sending
- Recharge account regularly
DLR Notifications #
You can enable push notifications for DLR updates:
iOS #
- Settings > SMSGatewayCenter > Notifications
- Enable “Delivery Reports” or “DLR Alerts”
- Choose notification style (Banners, Alerts)
Android #
- App Settings > Notifications
- Enable “Delivery Reports”
- Customize notification sound/vibration
Benefits:
- Get instant alerts when messages are delivered
- Know immediately if delivery fails
- Track important messages in real-time
Exporting DLR Reports #
To export DLR data for analysis:
- Go to Reports/History section
- Filter by:
- Date range
- Status (Delivered, Failed, etc.)
- Recipient number
- Tap Export/Share button
- Choose format:
- CSV: For spreadsheet analysis
- PDF: For reports and documentation
- Save or share exported file
Use cases:
- Analyze delivery success rates
- Generate reports for management
- Track delivery performance over time
- Identify problematic numbers
Troubleshooting DLR Issues #
DLR Not Updating #
Problem: Status remains “Pending” or “Sent” and doesn’t update.
Solutions:
- Wait longer: Delivery can take 5-10 minutes
- Check internet connection: DLR updates require internet
- Refresh reports: Pull down to refresh reports screen
- Restart app: Force close and reopen app
All Messages Show “Failed” #
Problem: Every SMS shows “Failed” status immediately.
Solutions:
- Check account balance: Low balance may cause failures
- Verify number formats: Ensure all numbers are in international format
- Check sender ID: Verify sender ID is approved and active
- Contact support: If issue persists, there may be account or system issue
Inconsistent DLR Status #
Problem: Some messages show “Delivered” while others show “Sent” only.
Solutions:
- This is normal: Some carriers don’t send delivery confirmations
- “Sent” may mean delivered: In regions without DLR support, “Sent” is often the final status
- Check with recipient: If confirmation is critical, verify with recipient directly