Microsoft’s Office 365 Exchange Online Protection (or EOP) can be used to easily manage the spam and malware filtering needs for an O365 tenant. It can even do this for an on-prem Exchange system.
The spam filter offers a number of configuration options including where to send messages that have exceeded the spam score threshold.
Sending them to quarantine is a great way to keep them from appearing within the recipients junk e-mail folder which is actually a default action on O365. Combining this with end-user spam notifications will send users an e-mail summarizing what was quarantined, including the option to release it to their own mailbox as well as mark as “not junk”, if in fact it is legitimate e-mail. To locate this option select the spam filter from EOP and look to the right of the screen, then scroll down until you see:
Here we can configure how often we wish to send the quarantine report
It is important to note that spam-quarantined messages are kept in quarantine for 15 days. Items that match a manually configured transport rule are kept for 7 days and then permanently deleted afterwards.
There are many benefits to filtering spam in the tenant rather than have it trickle down to the users junk e-mail folder. One of such benefits is that potential threats, often hidden within spam, are no longer automatically downloaded to a users spam/junk e-mail folder and cached within their mail client.
End-user spam notifications allow users to review, white list or release their own quarantined messages. This provides them control over their spam in a safe and simple manner.