sending bulk messages

Simultaneous sending of messages to several people, usually for campaigns.

sending bulk messages is the practice of sending the same message (or personalized variations) to many contacts at the same time. Done poorly, it leads to the number being banned within hours. Done well, it is one of the strategies with the highest ROI in Brazilian marketing.

The three non-negotiable rules

Consent — only send messages to those who have already had a relationship with the company and have the option to leave (opt-in + opt-out). Purchased list is illegal spam.
Heating — new number needs 7-14 days of actual use before sending messages.
Cadence — random intervals (15-60s) between sends, small batches, daily limit.

Number age limits table

Age	New messages/day	Interval
0-7 days	Do not send messages	—
7-30 days	up to 50	30-60s
30-90 days	up to 200	20-45s
90+ days	up to 500	15-30s

What NEVER to do

List purchased.
Same message for 1,000+ people with no text variation.
send messages from new number (without warm-up).
Multiple sends in the same second.
Messages without an unsubscribe option.

segmented messaging vs blind messaging

sending blind messages (generic message for the entire base) has a response rate of 1-3% and generates complaints. Sending segmented messages (specific message for specific tag) has a response rate of 8-20% and zero complaints.

See: Complete Secure Messaging Guide, segmentation, number warm-up.