SIP Address Doesn’t Match Email Address


By default if your Lync SIP address doesn’t match your primary SMTP email address, then Outlook integration will not work. You can resolve this by disabling the client policy DisableEmailComparisonCheck using the following PowerShell command.




  1. What are the consequences then? Does the Outlook integration simple not work, or does the system simply use other methods to discover the mailbox, thus increasing the time or load on other Lync components? I've just worked with some messed up environments where it's a mixed bag, some are "correctly" setup, others are not.

  2. Hey Andrew, Does this apply to the main SMTP address being an alias? We have an environment where the SMTP address is being used as the main SIP address but its not a different domain. This is causing some problems with voicemail and Windows Mobile integrations.

    • Hey Steven,

      From what I understand you are saying that both your users SIP address and Exhange SMTP address are the same i.e both are If this is the case then DisableEmailComparisonCheck does not need to be enabled. If you give me a bit more information about your scenario I may be able to help further.

  3. We are a bit stuck with Lync 2013. We are using the UPN for the SIP but the Domain name is different from the Email domain. Message history is correctly being saved in Outlook but Lync cannot find it when you click on a user and select ‘find message history’.

    Any suggestions greatly appreciated

    • I’m not 100% off the top of my head, but this may require EWS connectivity. Do you know if EWS is working? If you hold the control button and right click the Lync task tray icon you can select “Configuration Information”. Within that you are interested in the status of “EWS Information” and “MAPI Information” – what state are they in?

  4. Same as Steven; we have an environment where the used to be both e-mail adr. aswell as SIP but is now an alias and a new is the primary e-mail adr. and the users get a fault in SfB saying they need toprovide SfB with Exchange-credentials. Will your command help with this?