I want to try the office ATP add-on for my exchange online users
but I can't find the exchange online advanced threat protection (office ATP) in the list of the available add-ons in the add subscription part. (I can find all the others add on except this one)
My current subscription are around 100 E3 + 260 Business Premium (open volume agreement)
any clues, about the cause of this issue ?
Maybe you are looking for the wrong name? It should be listed under Add-On Subscriptions as "Office 365 Advanced Threat Protection". I am seeing it in multiple tenants of varying types, although at this URL it says to contact your reseller if you want to add it. https://products.office.com/en-us/exchange/online-email-threat-protection
You might have to contact your Partner / Reseller to get this feature enabled :) All the best