Hi all,

A user reported that when he tried to get the presence and chat with a partner which is using Skype For Business Online, he couldn’t get the presence and had an error when start to chat.

Whereas the partner can get the presence and initiate an IM with him…

We finally found that as we also got an Online Skype For Business with our SIP domain despite no records target it and no hybrid configuration as been setup, the list of allowed domains need to be the same between the on-premise environment and the online one.

So if you are in the same situation as mine, which is sharing the same SIP domains between on-premise and online tenant, with or without hybrid configuration; you have to allow the same domains for federation in order that you get no issue.