Exchange User Integration pack Throttling

Question

I noticed very recently that we are having issues when have multiple steps using the "Create and Send E-mail" step. We are getting the following error. Is there any way to cache the token or adjust the limits before the app gets throttled? It seems to happen around 15-18 emails. This has not been an issue and we have been running the same runbook for the last few year + and havent started having issues until 12/28. We haven't changed anything with our APP in Azure AD, haven't changed settings in Exchange online. What is the best route to go about here because I thought using the Integration pack was the best way to go.?

Your app has been throttled by AAD due to too many requests. To avoid this, cache your tokens see https://aka.ms/msal-net-throttling.

Exception: Exception
Target site: ExchangeGateway..ctor

Stack trace:
   at SystemCenter.IntegrationPack.ExchangeUser.Web.Core.ExchangeGateway..ctor(IExchangeConfiguration configuration)
   at SystemCenter.IntegrationPack.ExchangeUser.Activities.ExchangeActivity`1.Execute(IActivityRequest request, IActivityResponse response)

Answer 1

As the error message mentioned, this issue is not related to Orchestrator or Exchange. Instead, Microsoft Entra ID (AAD) throttles applications when the authentication API is called too frequently.

https://learn.microsoft.com/en-us/entra/msal/dotnet/advanced/client-and-server-throttling

Please review the following log for further findings:

https://learn.microsoft.com/en-us/system-center/orchestrator/exchange-users-integration-pack?view=sc-orch-2025

1. Set Log OAuth request/response to True if you wish to inspect authentication failures in detail. The logs will be generated on the path %windir%\Temp\sc-orchestrator\exchange_user\{date-time-stamp}.msal.txt. One file will be generated for each execution of an Exchange User activity.
2. Set Trace EWS request/response to True if you wish to inspect EWS failures in detail. The logs will be generated on the path %windir%\Temp\sc-orchestrator\exchange_user\{date-time-stamp}.ews-trace.xml.log. One file will be generated for each execution of an Exchange User activity. We recommend that you use SOAPe to visually inspect the traces.

We could add an interval time to the "Create and Send E-mail" step. Avoid making authentication API calls too frequently.