Outlook not connecting to exchange when on VPN

Site to site VPN as I mentioned works without any issues with 192.168.110.xx and 192.168.120.xx Those clients can reach Exchange with no problems, outlook doesn't prompt for a password. DHCP is not running in the MX84 location where Exchange server lives and where VPN clients are connecting to. Domain Controller has DHCP running. Why Can't I Connect My Outlook 2016/2019 To Exchange Jul 14, 2020 Anyconnect Outlook Disconnect Issues - Cisco Community

vpn-firewall> unset flow tcp-syn-check. Save the configuration. vpn-firewall> save. This resolved the problem for us and should resolve the Outlook & Exchange connectivity issues over VPN even if it is a different VPN device like Cisco ASAs but ofcourse use appropriate commands for those device.

Apr 29, 2020 Overview: VPN split tunneling with Office 365 | Microsoft Docs

How to fix Exchange & Outlook connection issues over IPSec VPN

Jul 31, 2019 How To Fix Outlook Connectivity Problems Jan 18, 2016