The SMPP PDU used by an SMSC to deliver incoming SMS messages or delivery receipts to an ESME.

Why deliver_sm Matters

This is how the other direction of traffic works: inbound replies from a handset, and delivery status for messages you already sent, both arrive as deliver_sm.

How deliver_sm Works

When a handset sends an MO message, or when a previously submitted message reaches a final state (delivered, failed, expired), the SMSC sends a deliver_sm PDU to the bound ESME carrying that message or receipt. The ESME acknowledges it with a deliver_sm_resp.

How SMPPCenter Uses This

SMPPCenter uses deliver_sm both to hand you delivery receipts for outbound campaigns and, on Two-Way SMS enabled numbers, to route inbound replies back to your system.

Related Terms

Client Feedback

What Our Clients Say

Our clients run regulated, high-volume messaging infrastructure and prefer not to be named publicly. These testimonials are shared with permission while keeping commercially sensitive details confidential.

The migration was completed smoothly and the platform has remained stable under heavy production traffic. The flexibility of self-hosting was one of the biggest advantages for us.
Head of Infrastructure, Financial Services Company India 18 million messages per month Runs SMPP Server Client since 2021
We evaluated several messaging platforms before selecting SMPP Center. The deployment flexibility and API capabilities matched our enterprise requirements.
VP of Engineering, Technology Company United States 20+ integrated applications Runs Enterprise SMS Gateway Client since 2020
High throughput, intelligent routing, and detailed monitoring have significantly simplified our messaging operations.
Operations Manager, Telecommunications Provider Kenya 8 million SMS per month Runs SMPP Gateway Client since 2023
The platform has been reliable for business-critical messaging. Multi-connection support and detailed logging have made daily operations much easier.
Infrastructure Manager, Enterprise Messaging Provider Russia 15 million messages monthly Runs SMPP Client Client since 2019

Names and company details are withheld at our clients' request. This is common among telecom providers, SMS aggregators, fintech companies, and enterprises that consider their messaging infrastructure commercially sensitive.

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