This is a follow upto an old thread from about a year ago: https://community.sophos.com/utm-firewall/f/network-protection-firewall-nat-qos-ips/126571/microsoft-teams-calendar-through-waf (that thread is now locked)
I've tried again to enable WAF for Exchange 2016 on-premise but encounter the same issue: mail flows fine, everything works for hybrid users in Exchange Online, but users with an on-premise mailbox can't see their Teams calendar (must be still something to do with EWS coming in to the Exchange on-premise from Teams).
Has anybody made any progress with this, or found a solution? I really want my Exchange 2016 servers behind the WAF rather than direct NAT rules. We're using the latest UTM firmware (9.711-5)
Thanks in advance!