For those companies who are not able to align their User Principal Name (UPN) and SMTP (Email) address, such as Email: firstname.lastname@example.org and UPN: email@example.com, you may find that your Lync/Skype for Business client is unable to pull free/busy information from Exchange Online. This is due to the difference in ‘logins’ and values, so the below option gives the machine’s Lync client the ability to ‘trust’ these different domains, providing the ability to properly pull IM/Presence and Free/Busy information.
Special thanks to Edward P. for the following information!
- Sign-out from Lync and Delete Sign-in info
- Exit Lync and exit Outlook
- Delete the Tracing , CEIP and sip_user folders in this path %localappdata%\Microsoft\Office\15.0\Lync
- Delete the Lync registry key from HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\
Manually modify the TrustModelData registry value for this user, Open CMD in Elevated mode and run the cmd below. Note that the below is for Office Lync 2013 client, using the \15.0 registry key.
Reg Add “HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\15.0\Lync” /V “TrustModelData” /T REG_EXPAND_SZ /D “ SMTPDOMAIN.com, SIPDOMAIN.com, online.lync.com, outlook.com, lync.glbdns.microsoft.com” /F
- Start Lync and sign back in
Note – If you are running in Exchange Hybrid Mode, you may have autodiscover.<emailDomain>.com pointing to on-premises Exchange. If this is the case, you will need to create and use a local PC HOSTS file, with autodiscover.<emailDomain>.com pointing to an IP address for this DNS A record: autodiscover.outlook.com, so your Lync client can connect into Exchange Online to properly pull the F/B information.