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What is the Lync Domain Name?

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I am setting up Lync for an Office 365 user. But when I just enter the email adderess for the user, it's also asking for a username. I tried entering the email address as the user name as well as domain\username . . . but neither one worked.


So what is the domain (fqdn) for Office 365 users when setting up Lync 2010?

Verified Answer
  • I forgot to mention that the REAL answer to this question is to use your SIP username which is usually your Office 365 email address . . . although, on occasion there is an error when setting up Office 365 accounts that will create the wrong username for Lync.  In this case, you have to open a support request through the O365 interface and request that your SIP username (i.e. what lync uses) be changed.  

All Replies
  • Hi direct,

    Please try the below options:

    First, it maybe a service called Microsoft Online Services Sign-In Assistant (IDCRL7) causing this issue. You can download it from the link below:

    Download the 32 bit version

    Download the 64 bit version

    After downloading and installing it, please log on Lync with your Microsoft Online Services ID to test the issue. If the issue persists, please move on the next step.

    Second, add the SRV record in the menu configuration:

    1. On the Lync 2010 sign-in screen, click the gear icon in the upper-right corner. This action opens the Options page.

    2. On the Options page, click “Personal” on the left panel, next to the Sign-in address box on the right screen, click Advanced.

    3. In the Advanced Connection Settings dialog box, make sure that Manual Configuration is selected and that the values in the boxes are exactly as follows:

    Internal server name or IP address:

    External server name or IP address:

    4. Click OK two times to return to the sign-in screen. Then, sign in.  

    I hope this can help you.

    Best Regards,

    Kylin Yang.

  • Sorry, those suggestions didn't work. When I went to install the Microsoft Online Services Sign-in Assistant, it said a newer version was already installed. And your second suggestion of manually entering the addresses didn't work either.  So the brand new office 365 is off to a wonderful start.  Can't even do something simple like sign in to instant messaging!

  • Just another example of how MS needs to offer small business users a means of direct support . . . even if it's only a certain number of incidents.  In this case, I followed the MS instructions exactly, but it doesn't work.  Is that my fault?

  • For the record, I was prompted tonight to install a Lync update (see link below), but installing that did not fix the problem.

  • Also, for the record, I have verified that this is a machine-specific problem, not a user problem.  I tried logging in on this problem machine with other user IDs that have been successful on other machines, but their logins did not work on this problem machine either.  

  • I also tried installing this hotfix, but it didn't help either!

  • I guess MS isn't willing or able to help on this.  

    As it turns out, when another user adds me as their contact in Lync, my IM address is listed as different from my email address for some reason.  But I don't see where to assign an IM address to a user.  Where can I change this IM address globally?  

  • With no help from Microsoft (outside of canned answers that don't apply), I figured out that somehow users were assigned a different IM address from their email address.  If someone knows where I can change the IM address, this will be resolved!

  • Hi Direct,

    Thank you for providing more information.

    Be notice that, you lync address is

    You can try to login your ID on other PC to have a try.

    If you can login lync on other pc successfully, it is indeed your client pc issue.

    Then would you please do a test by closing all other applications except Lync client on the issued pc, and making sure the ports are not blocked by any firewall or anti-virus applications or enter Safe Mode with networking by clicking F8 button of the keyboard when restarting your pc.

    If it still can't work, please help to collect some log information using the following method:

    1. Choose the dropdown menu in the upper right corner of lync, and select Tools>Options.

    2. Choose "General" in the pop window, go to the "Logging" title, and check the two options below.

    3. Click OK and Try to initiate a white board sharing . After the issue occurs, you should be able to find the log information from the path: %userprofile%\Tracing.

    Best Regards,

    Kylin Yang.

  • That is a canned answer that doesn't solve the problem.  The problem is that SOMEHOW when I setup 2 of our user accounts, it assigned their IM Address as different from their email address.  I have confirmed this by looking at the Outlook contact record created by Lync.  So the question for Microsoft is how could this have happened.  But the question for me is how do I change the IM address so that it matches the email address?  I don't see an option for this in the user admin section.  But any answer you provide outside of answering this specific question is not helpful.

  • I followed your instructions to turn on logging, which created a file, "Communicator-uccapi-0.uccapilog" (among other files).

    Within this file, the relevant lines appear:

    ... <snip /> ...


    ... <snip /> ...

    SIP/2.0 401 Unauthorized

    ... <snip /> ...

    Other suggestions?

  • Microsoft's own support documents address changing a SIP URI (Lync Username)  ... see point 2 under this topic at the following link.  It says we should contact Microsoft support to have this changed, but if small business users can't contact MS for support, how can we do this?

  • Hi direct,

     According to the log in issue, let’s do some operations to narrow down the issue.

    1. Could you provide the version of Office 365 you used? P1 for small business or E3 for enterprise?    

    2. If you use your own Lync address(The same as you log in Microsoft Online Portal) and password to log in your Lync on other pc in which can be logged in successfully by other person with their Lync, can you succeed to log in?

    3. If you input your Lync address and password to log in Lync, once you cannot log in successfully, you will receive an error message, what is it? Could you paste an error screenshot using rich formatting mode of the Forum for us?

    4. Could you ensure the ports are not blocked by any firewall or anti-virus applications? Have you tried in safe mode?

    5. Can you collect some log information for us?

    6. You can download the tools of MOSDAL (Microsoft Online Services Diagnostics and Logging) Support Toolkit in to do some “Data Collection” and “Network Diagnostics”.

    7. How to troubleshoot authentication and connectivity issues in Lync Online, please refer to the link:

    We hope you could provide us more information, so as to we can do more research for further investigation.



    Kylin Yang.

  • We really don't need to go through all that as the cause has been determined already if you look at previous posts.  The problem is that for some reason 2 of our Office 365 users were assigned their Windows Live Messenger usernames as their Lync usernames.  So their SIP usernames need to be changed. And again as noted above, the only way to do this according to Microsoft's own documentation is to contact MS support directly.  So I'm not exactly sure why you provided canned steps for troubleshooting.  

  • Hi,

    There is a known issue when you use the same domain in Windows Live services and Office 365. Please use a different domain in Office 365 if this is the case.

    Best Regards,