Configuring the SSL certificate to SharePoint 2016

Hi everyone.

Last week I was having fun installing a Project Server 2016 for a customer, and after creating a workflow, I started to receive an error when the workflow tried to send an email to my user.

So, the first thing I did was open the ULS log, and I found the following error:

Failed attempt 1 sending mail to recipients: “User Name” <>. Mail Subject: Task Assigned – Approval: Test Diego Workflow. Error: Exception while sending email: System.Security.Authentication.AuthenticationException: The remote certificate is invalid according to the validation procedure.”

The certificate was imported following the SharePoint 2016: Step by Step guide to add Workflow Manager Certificate into SharePoint trust

But there is a problem when you export from the ISS site, then I removed the certificate and imported a new one.

Removing the Certificate:

  • Access the SharePoint Server and open the ISS -> Sites -> Workflow Management Site, and check the port. (It should be 12290)
  • Now open the PowerShell as Administrator.
  • Run the following command: netsh http show sslcert. You will see something like the image below.


  • Save the Application ID number and the IPPort
  • Remove the certificate using the following command: netsh http delete sslcert ipport=

Importing a new certificate:

  • Open the certificates on the Local Computer and copy the Thumbprint number


  • With the Thumbprint number, you will run the following command on the PowerShell:
  • First run: netsh
  • Then: http
  • add sslcert ipport: certhash=ThumbprintNumber appid={APP ID NUMBER SAVED BEFORE}
  • Remember to remove the spaces from the Thumbprint number


Ther certificate part is done now.

Then I tried to rerun my workflow and the second error received was: Server does not support secure connections.


That was an easy one. It’s about the SMTP configuration. To fix, open the SharePoint Central Administration -> System Settings and click on Configure Outgoing e-mail settings.

Update the TLS connection encryption to No.


After that, everything was working perfectly.

#ProActive  #JoinUs #PMOtto

Diego Pereira

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