We have an instance of Sitecore 8.2 update 5 using XDB cloud and EXM hosted in Azure using PaaS AppServices.

I am testing EXM and trying to send test email campaigns from our CM instance. However even through EMX reports the campaign has been successfully and sets the status to “sent” zero emails are actually sent.

I have uploaded a test CSV document with the first name, last name and email of all the developers in my team, a total of 9 contacts, and I can see using Robo mongo these contacts are in the analytics set in XDB Cloud. What’s more confusing is that I can sent a test preview message from the Review tab. That works fine.

Trawling through Application insights, I can see a common error...

6756 16:53:04 WARN  Unhandled exception thrown while processing task '0xBB3AF911DC384345AA2C16966CF4BF17' **from task pool 'dispatch_failed_task_pool'. The task has not reached the maximum number of attempts to process a failing task and is postponed.**

Exception: System.ArgumentException

Message: **Null ids are not allowed.**

Parameter name: **contactId**

Source: Sitecore.Kernel

The contactID parameter is odd as the contacts use the email address and the contact unique identifier.

I have an ongoing support ticket open with Sitecore but they are struggling to resolve this.

Can anyone shed any light on this?

  • can you check if the The EXM.CryptographicKey and EXM.AuthenticationKey are identical on the CM and the dispatch server? Commented Mar 5, 2018 at 19:44
  • we are using EXM cloud so we don't use our own dispatch server (im assuming?) but i will ask support this as we have a ticket open
    – JGilmartin
    Commented Mar 5, 2018 at 21:29
  • hey @JGilmartin, does it help you my recommendation? Commented Mar 8, 2018 at 4:46
  • @VladIobagiu - thank you, this was the issue, after i updated the connection strings config of the dispatch server it then worked
    – JGilmartin
    Commented Mar 8, 2018 at 13:15
  • I will add my answer, please mark my answer as correct, maybe others will have similar issue in the future Commented Mar 8, 2018 at 13:28

1 Answer 1


Your issue appear because you have different values (or it doesn't exist) for EXM.CryptographicKey and EXM.AuthenticationKey settings.

Please add bellow settings into dispatch server connection string :

<add name="EXM.CryptographicKey" connectionString="yourCryptographicKeyfromCM" />
<add name="EXM.AuthenticationKey" connectionString="yourAuthenticationKeyfromCM" /> 
  • Vlad, im still confused between the role of the DDS and that we are using EXM cloud/SparkPost to send our emails, can you post a comments with any links that describe in detail the role of the DDS server?
    – JGilmartin
    Commented Mar 9, 2018 at 10:43

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