Relevant products: Signature Manager Exchange Edition, Signature Manager Outlook Edition, Mail Archiver, Mail Disclaimers, Signature Manager.
WARNING! From 1st April 2021 Exclaimer will no longer be renewing any Software Maintenance Agreement (SMA) for Mail Disclaimers.
Please be assured that the Exclaimer Support team will provide support until your SMA is active.
However, we recommend that you contact the Exclaimer Sales team to discuss your requirements for an upgrade to Signature Management Exchange Edition or Exclaimer Cloud - Signatures for Exchange.
You have an Exclaimer on-premises product that utilizes Exchange Web Services (EWS) that is installed on the same Exchange server that it connects to using EWS.
You notice that these connections are failing and an EWS error stating 401 unauthorized is logged - despite the service account being used and having the appropriate permissions in the Exchange environment.
This error is caused by Microsoft's workaround for CVE-2018-8581 which is automatically applied as part of security or Exchange Cumulative Updates (CU); for more information, see CVE 2018 8581.
You can resolve this issue in either one of the following ways:
- Use the following manually specified Exchange URL: https://localhost/ews/exchange.asmx
- Configure a BackConnectionHostname.
Follow the steps outlined in Method 1 (recommended): Create the Local Security Authority host names that can be referenced in an NTLM authentication request.