HCW8039 The hybrid Send connector must only contain the single address space error when you run HCW

Original KB number:   3087172

Problem

When you run the Hybrid Configuration wizard (HCW), you receive the following error message:

HCW8039 The hybrid Send connector must only contain the single address space '{0}'

Cause

This issue occurs if the Send connector that's created by the Hybrid Configuration wizard has additional namespaces added to it.

Solution

To resolve this issue, follow these steps:

1. Open the Exchange Management Shell.

2. Run the following command:

   Get-SendConnector -name "Outbound to Microsoft 365"
   

3. In the output, examine the value of the AddressSpace parameter. You should see either "*" or "contoso.mail.onmicrosoft.com;1."

4. If you see any addresses other than "*" or "contoso.mail.onmicrosoft.com;1", remove them. To do this, run the following command:

   Set-SendConnector -name "Outbound to Microsoft 365 "smtp:contoso.mail.onmicrosoft.com;1"
   

5. Run the Hybrid Configuration wizard again.

More information

Still need help? Go to Microsoft Community or the Exchange TechNet Forums.