The library uses underlying OS stack. If OS does not support it you get this error.

Fixed in [2.9.37] - 2026-02-04
- Could not load assembly on MacOS. The access code is invalid.

all TLS versions, supported by target framework

the issue has been fixed in 2.9.36

Hi IoJo,

Could you share one or two screenshots from your memory profiler, especially the “Path to GC root” for SubmitSm?

Please clarify:
- whether the retained objects belong to internal Inetlab collections or your own structures.
- whether the retention continues even after the SMPP client is ...

Hi

You can use WorkersTaskScheduler class instead of WorkerThreads property.
https://docs.inetlab.com/smpp/v2.9/arti ... uning.html

Delivery Reports can be received with evDeliverSm event.
https://docs.inetlab.com/smpp/v2.9/arti ... ceive.html

The problem may be related to your payment provider or bank declining the transaction. Some common reasons for this include:

- Insufficient funds
- Bank security flags (possible fraudulent transaction)
- Incorrect CVV or card details
- Generic declines from the bank

Please check if your card ...

Hi,

In this context, "message" refers to a single SubmitSm PDU.

To evaluate performance, you can use the following metrics:

_smppClient.Metrics.Sent.Request.PerSecond;
//or
_smppClient.Metrics.Sent.Request.AvgPerSecond;


For more details about built-in metrics, please visit the
https://docs ...

Hi Luis,

Yes, you can create a single instance of the MessageComposer class for the SMPP server. The class is thread-safe, allowing you to add different messages concurrently.
The composer uses a combination of the source address, destination address, and message reference number as a unique key ...

Hi Ben,

The code is correct.

I would check the captured PDUs in wireshark.

If you still has this issue please write me to e-mail support@

You need to enable ProxyProtocolEnabled for the client in the handler method for the event evClientConnected


smppServer.evClientConnected += (sender, client) =>
{
client.ProxyProtocolEnabled = true;
};


after that the RemoteEndPoint of the client returns the IP address behind the proxy.

SendSpeedLimit can only help to prevent the throttling error ESME_RTHROTTLED

When you get the Message Queue Full error status ESME_RMSGQFUL, you have to limit the number of SMPP requests waiting for response with the property SendQueueLimit

You can use See example

It looks like the property ScheduledDeliveryTime or ValidityPeriod has incorrect value in SubmirSm instance.

Could you help me to reproduce the error?

I think the same exception should be thrown when you set the values for SubmitSm instance and try to serialize it

ver byteArray = submitSm ...

Hello,

Inetlab.SMPP library provides two extension methods CanBeDecoded , CanBeEncoded

https://docs.inetlab.com/smpp/v2.9/api/Inetlab.SMPP.Encodings.EncodingExtensions.html

With these methods you can check if text can be encoded with specified encoding or if the byte array can be decoded with ...