Lync Login Help

Please try this tool from Microsoft to analyze the connectivity to the Lync servers
https://testconnectivity.microsoft.com
1) Select "Lync / OCS Server" 
2) Select "Lync Server Remote Connectivity Test"
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In addition, you can verify the Lync system information by holding down Ctrl and right clicking on your Lync system tray icon and selecting ‘Configuration Information’.

• Use 'Connected Lync Server' or 'Server Address External' as your server name
• Use the Server SIP URI to confirm your email
• In some cases you may also need to enter your Windows Domain and Username.  Please use the same domain\username you use when you login to your PC.