Sending best practices

WhatsApp bans robotic behavior proactively. bZapper does a lot for you — rotation, volume ramp-up, pacing, automatic pause — but the final outcome depends on how you use it. This guide gathers the practices that protect your numbers the most.

Rule number one

High volume on a single number is what gets you blocked the most. Spread it across several numbers (redundancy) and give each one time. A healthy pool is what sustains delivery.

1. Only send to people who consented

The root cause of most bans is unsolicited messages. Someone who doesn't recognize the sender reports it — and a report is the strongest signal for WhatsApp to block.

• Collect a free, informed and unambiguous opt-in (see Privacy & LGPD).
• Never buy lists or import contacts who didn't ask to receive.
• Let opt-out work: whoever replies STOP/SAIR/PARAR is suppressed automatically and must not return to the base.

2. Ramp up a new number

A freshly connected number doesn't blast messages. bZapper puts every new number on a ramp-up: a daily cap that grows gradually. Respect it.

• Start with few messages per day and ramp up.
• Prefer real conversations (back and forth) at first — not just broadcast.
• Only give volume to a number after it matures (we recommend 7+ days).

3. Keep a healthy pace

Sending everything at once is intrusive for whoever receives it. bZapper applies pacing between messages and respects a time window (8am–9pm) when sending to lists. Help it out:

• Don't force bulk sends outside business hours.
• Vary the content — use variables ({name}, {amount}) so the message ({Hi|Hello|Hey}) so two people don't get identical text. See Campaigns.
• Prefer the conservative pacing_profile when the base is cold or new.

4. Rotate across several numbers

A pool with rotation spreads the load and takes at-risk numbers out of circulation — automatically. That's why list sending requires 2+ numbers connected and past ramp-up.

• Available strategies: round_robin, least_used, health_weighted.
• Each number has a live health score; rotation favors the healthy ones.
• Conversation affinity (sticky): once a number talks to a customer, it keeps going — the conversation doesn't "jump" between numbers.

5. Read the block signals

bZapper watches the signals and acts before the ban:

• Smart pause — if messages stay at "sent" and never reach "delivered", the campaign pauses on its own and you're warned (webhook campaign.paused).
• Inferred block — numbers in that state enter suppression as blocked_inferred (they block in the account's strict mode).
• Drop alerts — when a number drops or is banned, you get a real-time alert.

If a number starts failing, don't push it: let it rest and let rotation take over.

6. Always respect suppression

• Whoever asked to leave stays out — the block list stops the send before queuing.
• Blocks by opt-out or manual are a wall: they don't get through even with force.
• Sync the contact.opted_out webhook with your CRM so you don't try to re-import.

Antipatterns that hurt delivery

❌ Avoid	✅ Do
Buying/scraping lists	Collecting opt-in with proof
All volume on one number	Rotating across 2+ numbers
Giving high volume to a new number	Respecting the ramp-up first
Identical text for everyone	Variables and content relevant per contact
Ignoring who said STOP	Letting opt-out suppress
Pushing a failing number	Letting it rest and rotating
Sending around the clock	Controlled pacing, time window

Ready-made tooling

Many of these practices are already built in: list sending applies pacing, load spreading, ramp-up, smart pause and suppression on their own. See Campaigns and the delivery concepts.