Skype for Business Server Side conversation history for Exchange Online users not working

Hello Ivan,

Thank you for your reply.

Changing "ExchangeAutodiscoverUrl" to "https://autodiscover-s.outlook.com/autodiscover/autodiscover.svc" solved the problem. But, as far as I remember from some documentation, "ExchangeAutodiscoverUrl" in the hybrid Exchange configuration should point to the on-prem exchange autodiscover.

As I understand, now every request for saving the conversation in the history is traveling over the Internet and for on-prem users is redirected back to the on-prem Exchange. Currently, most of our users are located on-prem, so I also want to try to set "ExchangeAutodiscoverUrl" to on-prem Exchange, and specify the "*.company.com","*.outlook.com","*.company.mail.onmicrosoft.com" in the "ExchangeAutodiscoverAllowedDomains" parameter.

Thank you for pointing me to the right direction.