Hello Michael, It's been a couple of years since my last organization migrated in a Hybrid scenario to Office 365. We had a Cisco Ironport device that handled email content similar to the Sophos UTM. We set up send and receive connectors to the Cisco Ironport that was in-between Office 365 and our on-Premise Exchange servers. Eventually we phased out the Ironport and had all filtering done by Office 365.
Sophos Utm Community Download
I can say that when we configured our email to go through Office 365 we HAD to change the MX records to point to their servers. Not sure you can set up your Sophos UTM as the main MX and then route through Office 365. You may get errors in Office 365 when it checks for your domain's DNS settings.
Sophos UTM drives threat prevention to unmatched levels. The artificial intelligence built into Sophos Sandstorm is a deep learning neural network, an advanced form of machine learning, that detects both known and unknown malware without relying on signatures. RE: ATP Alert Generated for DNS Lookup of hosts specified in UTM Block Rule. 2 days ago Recommended Reads This curated forum is to highlight content created by the Community or by Sophos.
Here is a great step by step help article for you or your clients for installing and logging into the Sophos SSL VPN Client. Step 1: Open your preferred web browser (Ex: Google Chrome) Step 2: At the top of your browser in the address bar, enter the public IP address of your network (Ex: https://169.254.30.211). Sophos UTM drives threat prevention to unmatched levels. The artificial intelligence built into Sophos Sandstorm is a deep learning neural network, an advanced form of machine learning, that detects both known and unknown malware without relying on signatures. Status page provided by StatusCast. closed Latest Status Update: 4/1/21 19:00 UTC - At approximately 18:00 EDT / 22:00 UTC on 3/26/21 a maintenance script was executed on Sophos Central that caused a number of Partner Administrator accounts to lose their role assignments and as a result Partner/Customer User accounts affected by this issue may not have visibility to data, including.
I would keep the MX pointed to Office 365, set up send and receive connectors back to your Sophos device as a middle-man.
Sophos Utm Appliance
The link below has some good guidance.
Sophos Utm Home Edition
Mail flow best practices for Exchange Online and Office 365 (overview)
That's my take.
Sophos Utm Download
Hope it sheds some light .