Implement Double Opt-in (Proactive Measure):
Practice: This is the most effective initial hygiene measure. After a user submits their number, send a confirmation SMS asking them to reply with a keyword (e.g., "YES") or click a link to finalize their subscription.
Benefit: Immediately filters out mistyped numbers and less committed individuals, ensuring only genuinely interested, valid contacts are added.
Automate Hard Bounce Removal:
Practice: A "hard bounce" means a message permanently failed to deliver (e.g., the number doesn't exist, it's invalid, or disconnected). Your SMS marketing platform should automatically identify and permanently remove these numbers from your active list.
Benefit: Prevents repeatedly sending to non-existent numbers, a major red flag for carriers.
Monitor and Manage Soft Bounces:
Practice: "Soft bounces" are temporary delivery failures (e.g., full inbox, temporary network error). While they might resolve, consistent soft bounces from the same number indicate a persistent issue.
Benefit: Set a threshold (e.g., 3-5 consecutive soft bounces over south africa phone number list a month) after which the number should be moved to a suppression list or flagged for review.
Implement an Inactivity Management Process:
Practice: Identify subscribers who haven't engaged with your SMS messages (no opens, clicks, or replies) for a defined period (e.g., 6-12 months).
Benefit:
Re-engagement Campaign: Send a specific "We miss you!" SMS with a strong incentive or a direct question ("Still want our updates? Reply YES!") to reactivate them.
Suppression: If they don't respond, move them to a suppression list (don't delete entirely, just stop sending marketing messages) to prevent unwanted future communications.
Utilize Phone Number Verification Services:
Practice: For newly acquired lists, or large lists where consent verification is complex, use third-party phone number verification APIs or services. These tools check numbers against global databases to confirm validity and active status.
Benefit: Cleans existing lists in bulk, identifying invalid numbers before you incur sending costs.
Ensure Flawless Opt-Out Handling:
Practice: The moment a subscriber replies "STOP" (or similar), their number must be immediately and permanently added to your "do not contact" list within your platform.
Benefit: Ensures legal compliance, respects user preferences, and prevents complaints.
