Interopability of ECOS and M365

[KIT IT Services 0]

Hi all, 

Would anyone be able to shed some light on how effectively ECOS works alongside M365 Exchange. We are in the process of deploying ECOS to our large retail client but I'm struggling to get any bone fide documentation or advice on how the already existing M365 EOP rules may work alongside the ECOS rules. I've been told by a support person at ESET already that M365 is advised to be turned off but we would rather not do this without getting full confirmation of the ability of ECOS to scan all email traffic and make sure it is verified etc. I also saw a forum post in regards to the best solution having both products running side by side as 2 layer of defence. 

Does anyone have any advice for this at all? Thank you.

[Marcos 5,132]

ECOS scan email that is passed to it by Microsoft 365 through Microsoft Graph API. Not sure if there can be situations when Exchange doen't pass an email message further via the API though. Maybe ECOS developers have some experience with it so the technical support could reach out to them and find out if the developers have experienced cases when a message was not delivered via the Graph API for scanning at all.

[QuickSilverST250 0]

We were also advised to run ecos only, personally we run both MS365 and ECOS, but only standard security on MS 365 as a second layer incase eset misses something. W ceps domian spoofing enabled as when we disabled this our clients got some spoof mails so switched this back on for all clients. We found no issues in mail delivery, eset catches most but we do see now and then mail quarantined by defender. It does take to login in 2 systems, but this works for us.