Throttling SMS in Morocco: How fast can you really send your messages

Result: After a few seconds, the API rejects you with an error HTTP 429 Too Many Requests. The few thousand messages that have passed are blocked with a status Pending for 2 hours, and your delivery rate collapses.

This is the effect of Throttling (network congestion). Whether by API security or by physical limitation of telecom operators, sending SMS is not an unlimited stream. Here are what are the real sending speeds in Morocco, and how to design your systems to meet them.

There are two major congestion gaps in the sending architecture:

1. Rate Limiting HTTP: To protect its servers from DDoS attacks, the provider [SMS API] (/fr/api-sms-maroc/) limits the number of incoming requests per second (RPS) for a given API key.
2. Maroc Operators’ SS7 Throttling Network Limit: Maroc Telecom, Orange and inwi allocate a specific bandwidth (a Transactions Per Second – TPS) to each provider’s route.If the provider floods the operator’s gateway with far more messages than the channel was sized for, the operator places the messages in a waiting line (thus endless ‘Pending’ status) or rejects them to preserve critical network flows (emergency calls, banking OTPs).

Adjusting your technical expectations helps to avoid disasters in production.

• Basic REST API (HTTP): The limit is counted per key; at EnvoiSMS, 60 to 1,200 requests per minute depending on the plan (Starter 60, Business 180, Pro 500, Enterprise 1,200), raisable on request.This is perfect for transaction sending (OTP, validations, alerts), but not suitable for “locking” on a basis of 100,000 contacts.
• Endpoint Bulk API: Instead of sending 1 number per HTTP query, you are sending a 1000-number JSON table in a single query.
• Direct SMPP Connection: Asynchronous TCP protocol used by large companies. Throughput is purchased. It is negotiated route by route; at EnvoiSMS, SMPP is offered on request to high-volume accounts.

Rather than trying to force the API door, good engineers smooth up traffic.

Example of calculation: You have a list of 50 000 contacts. You want the campaign to start in the afternoon, before 18h. It is 14h. - Available time: 4 hours (14 400 seconds). - Required speed: 50 000 / 14 400 = ~3,5 SMS / second.

Instead of saturating the network, schedule a Cronjob or a [Horizon/Redis] (/fr/blog/build-a-file-d- wait-sms-resiliente-avec-redis-laravel/) configured to send at a steady pace, under your key's per-minute limit. Not only will you not trigger any API filtering, but the local operator will forward your messages with maximum priority because the traffic will look organic and healthy.

During major national events (Aid Watch, Black Friday), Moroccan operators face an exceptional overall burden.

1. Delivery times get longer.
2. The operator may decide to unilaterally lower the permitted TPS for marketing flows (Bulk) in order to prioritize voice and bank flows.
3. If you send your massive campaign at 5 p.m., it is likely to be in line until 10 p.m.

Good B2B Practice: Cut off your marketing list. Send 20% of your base at 10 a.m., 30% at 12 a.m., and 50% at 15 a.m. This guarantees perfect delivery, careful reading, and you spread the burden on your own customer service (which will receive the calls back as they go).