Spam, junk, and malicious emails are filtered by Exchange Online Protection using algorithms that match known behaviour against incoming email. You are notified of email filtered by this system in a periodic "Spam Notification" email.
Email that has got through this filtering is then subject to your own mailbox rules, with filtered email going into the Junk E-mail folder.
You are able to manage your junk and spam mail settings in a number of ways described below using Outlook or Webmail.
In Microsoft Outlook
In Outlook you can right-click the email in your inbox list and use the Junk menu to view various options to manage the message.
Blocking the sender will only stop email coming from that specific email address. If you choose the Report Junk option, the email will be sent to Microsoft to train the blocking system in what to block in future - this option is highly recommended.
If you select Junk E-mail options from the list you are able to manage in depth how your junk email is handled.
For Outlook Web App instructions please click here.