Bulk Messaging Done Right: Avoiding Spam & Maximizing Delivery

The #1 Rule: Only Message Opted-In Contacts

Before anything else: only send messages to people who have explicitly opted in to receive messages from you. This is both a legal requirement (GDPR, TCPA) and essential for avoiding platform bans.

List Hygiene

• Remove unsubscribed contacts immediately
• Validate phone numbers before import
• Segment by engagement: customers who opened in last 90 days convert 3x better

Content Best Practices

• Personalize with the customer's name at minimum
• Keep it short: under 160 characters for SMS, under 400 for WhatsApp
• One clear call-to-action per message
• Include opt-out instructions

Timing

• Best times: Tuesday–Thursday, 10am–12pm and 2pm–4pm (local time)
• Avoid Sundays and public holidays
• Use WaSMS's time-zone-aware scheduling

Monitoring

Watch your delivery rate (target: >95%) and opt-out rate (target: <0.5%). If opt-outs spike, pause and review your content and list quality.