One User who is sending SPAM

Occasional Contributor

So we have one user who seems to be spamming many other users. I figure its something local to his machine, malware etc. I have adjusted spam settings for the domain but I was wondering if there is anything I can do to limit the amount of spam he is sending out from 365?

4 Replies
Reset the users password and have a look at antispoofing settings, SPf record etc..

Hi Gary,


To follow up on what Adam has said



There is also third party solutions such as Mimecast which offer Internal Email protect between the users mailboxes which ought to cut down on a lot of it if you decide to go the third party route.


Because it could be a breach I would also consider some additional steps such as scanning of the machine with a reputable endpoint solution, activating credential and device guard if using Windows 10 and enrolling their devices into Intune in order to manage and protect their devices against modern threats.


Hope this helps


Best, Chris

Hello Gary,


Could you please give us little more information on in which app in 365 the spams are routed? 

Hi @Gary Choinski


I would strongly suggest backup and refresh of the O/S to wipe out any offending malware/virus that he may have on his computer.


Putting stop gap measures in doesn't solve the issue which is still compromising your system security, and you limit any risk of the issue spreading to other devices.


Better to play it safe and wipe the computer and educate the user on the dangers of installing unknown software and opening unknown email attachments, etc.


Good luck!