I don't know much about Lync and Outlook. We are currently using an Exchange 2010 server, and are slowly migrating to Office 365 (we'll be using that server and cloud based exchange soon).

We have installed Skype for Business on the PCs, and they work fine with our Office 365 Lync server, but the Mac is having an issue. I am using Yosemite 10.10.4 and Lync 2011 (14.1.1).

It connects to Lync just fine, but as soon as I log in, I get the prompt:

Credentials are required
Type your user name and password to connect fro retrieving calendar data from Outlook.

It prompts over and over again. I am not sure how to get it to work. Because the Lync Office 365 server is in the cloud, I cannot type domainname\username in the user ID box. I can only use myname@mydomain.com.

Also, previously our UPN suffix used to be @mydomain.local, and might still be, but I can't log in with that either. And I don't know if this is causing an issue as well. 

I'm kind of stumped, and am not sure what else I should do.

I also bumped the NTLM authentication to the top in the list of EWS Authentication in IIS, but it didn't seem to make a change. We have the latest rollup for Exchange 2010.

Hi,

1. Do other people using the Lync for Mac (14.1.1) encounter this issue?
2. Check the primary email address configured in Outlook desktop client matches the Lync SIP address
3. Make sure you have installed all patches for OS, Outlook and Lync.
4. Please check if you can sign into Lync client on another Mac with the same account.
5. If possible, please perform a clean uninstall of Lync for Mac 2011 via the link below, and remove all Lync entries from your Credential Manager. Then sign in with your full email address to see if the issue persists:https://support.microsoft.com/en-us/kb/2691870

Best Regards,
Eason

Easton,

Thank you for your reply!

1. Yes, other people using Lync 14.1.1 for Mac are getting this.

2. In Outlook the E-mail address is in the format of: firstname.lastname@domain.com and our user name is: domainname\firstname.lastname.
In Lync the Email Address is: firstname.lastname@domain.com and the User ID is also: firstname.lastname@domain.com
I can't use domainname\firstname.lastname as the User ID in Lync.

3. All updates have been installed both on Apple's end, and on the Microsoft end there are no updates available.

4. I tried Lync on another Mac (only it's using Outlook 2011), and it does the same.

5. Clean uninstall and reinstall did not help.

Also, if I'm looking at the Logon domain settings under owa (Default Web Site), I know Lync doesn't use this, but it says it uses forms-based authentication with User name only, and the logon domain is: domainname.local.

I am wondering if Lync isn't working correctly, because Exchange is using the domainname.local UPN.

That was it! I added an alternative UPN suffix, and then within Exchange I changed my User logon name from @domain.local to @domain.com.

Out of curiosity, how will changing the UPN in Exchange on my user account from @domain.local to @domain.com affect my user, as well as logging into a computer?

This probably won't be an issue soon, when we move completely to Office 365 with Exchange, but for the time being, I am not sure how switching everyone's UPN will affect them in the future.

• Edited by jrmoat 11 hours 52 minutes ago
• Marked as answer by jrmoat 9 hours 16 minutes ago

That was it! I added an alternative UPN suffix, and then within Exchange I changed my User logon name from @domain.local to @domain.com.

Out of curiosity, how will changing the UPN in Exchange on my user account from @domain.local to @domain.com affect my user, as well as logging into a computer?

This probably won't be an issue soon, when we move completely to Office 365 with Exchange, but for the time being, I am not sure how switching everyone's UPN will affect them in the future.

• Edited by jrmoat Monday, August 03, 2015 7:32 PM
• Marked as answer by jrmoat Monday, August 03, 2015 10:09 PM

That was it! I added an alternative UPN suffix, and then within Exchange I changed my User logon name from @domain.local to @domain.com.

Out of curiosity, how will changing the UPN in Exchange on my user account from @domain.local to @domain.com affect my user, as well as logging into a computer?

This probably won't be an issue soon, when we move completely to Office 365 with Exchange, but for the time being, I am not sure how switching everyone's UPN will affect them in the future.

• Edited by jrmoat Monday, August 03, 2015 7:32 PM
• Marked as answer by jrmoat Monday, August 03, 2015 10:09 PM

That was it! I added an alternative UPN suffix, and then within Exchange I changed my User logon name from @domain.local to @domain.com.

Out of curiosity, how will changing the UPN in Exchange on my user account from @domain.local to @domain.com affect my user, as well as logging into a computer?

This probably won't be an issue soon, when we move completely to Office 365 with Exchange, but for the time being, I am not sure how switching everyone's UPN will affect them in the future.

• Edited by jrmoat Monday, August 03, 2015 7:32 PM
• Marked as answer by jrmoat Monday, August 03, 2015 10:09 PM