Knowledge Base

How to avoid proxy-related issues when using the Sent Items Update service


The Sent Items Update (SIU) service is unable to process messages because of the proxy configuration, therefore all messages in Sent Items folder are not stamped with the signatures. Also, you are unable to configure the service correctly, as you are receiving the following error:

The request failed. The remote server returned an error: (407) Proxy Authentication Required.

Fig. 1. The error visible in CodeTwo Exchange Rules Pro 2.


Firstly, please check if the account used for Sent Items Update service is allowed to go through your proxy, because the problem may be related to the security restrictions of your network. If the problem persists despite the proper configuration of your proxy you can reconfigure the service manually. Please follow the steps described below:

If you are using CodeTwo Exchange Rules software of version prior to PRO 2.3.0, 2007 4.3.0, 2010 3.3 or 2013 2.3, please update your installation immediately by downloading and running the latest version of relevant installer. All steps described in this article are no longer eligible for those outdated versions.

  1. Go to the configuration folder of CodeTwo Exchange Rules. By default it is:
    %ProgramData%\CodeTwo Exchange Rules\Config\
  2. Open SentItemsUpdate.Service.xmlfile in any text editor, e.g. Windows Notepad
  3. Locate the following entry:
    <EWSUrl i:nil="true" />
  4. Modify it so it contains the proper EWS address as IP address (e.g.


    or FQDN (e.g.

  5. Save the file and restart the SIU service. You can do this in Window Services menu (services.msc).

If you do not know how to find the EWS address please familiarize yourself with this article

See also:

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