Possible Reasons for Non-Delivered Campaigns and Messages
This error may occur due to one of these reasons:
• The recipient phone number is not a WhatsApp phone number
• Recipient Phone Number has blocked your business
• Recipient has not accepted WhatsApp's new Terms of Service and Privacy Policy.
• Recipient using an old WhatsApp version; must use the following WhatsApp version or greater:
◦ Android: 2.21.15.15 ◦ SMBA: 2.21.15.15 ◦ iOS: 2.21.170.4 ◦ SMBI: 2.21.170.4 ◦ KaiOS: 2.2130.10 ◦ Web: 2.2132.6
• The message was not delivered to create a high quality user experience.
WhatsApp imposes a max limit of marketing template messages that a contact can receive in a certain time across all businesses. You can read more about this here - Per-User Marketing Template Message Limits.
How to solve this?
Using a non-WhatsApp communication method, ask the WhatsApp user to:
• Confirm that they can actually send a message to your WhatsApp business phone number.
• Confirm that your WhatsApp business phone number is not in their list of blocked numbers (Settings > Privacy > Blocked or Blocked contacts).
• Confirm that they have accepted WhatsApp's latest Terms of Service (Settings > Help, or Settings > Application information will prompt them to accept the latest terms/policies if they haven't done so already)
• Update to the latest version of the WhatsApp client.
List of errors with reasons and possible fixes
"Message undeliverable":
The recipient phone number is not a WhatsApp phone number.
Recipient has not accepted our new Terms of Service and Privacy Policy.
Recipient using an old WhatsApp version; must use the following WhatsApp version or greater
Since there is no real "fix" to this, the only thing that can be done is to create a Segment within "Audience" and choose "cannot receive message" under "activity. This segment can then be used to collect data of customer who have faced this issue, who then can be either deleted from the databank or be opted out. There is no way to predict how many contacts will face this issue or who these contacts are, it can only be found out by trial and error.
"Message failed to send because more than 24 hours have passed since the customer last replied to this number":
Sending a message after 24hours qualifies as outbound message, which is possible, but only via templates. The flows for delays over 24hours need to be adjusted accordingly to fix this issue.