Spam filtering and virus protection are automatically enabled on all inbound and outbound email messages by Microsoft Exchange Online Protection (EOP), the anti-spam and anti-malware service included with Office 365. The EOP service applies multi-layered filters and scanning engines to help protect your organization from email-borne threats. No admin setup or management is required for Office 365 Small Business.
How does spam filtering work?
Every message, inbound and outbound, is assigned a spam confidence level (SCL) based on the likelihood that the message is spam. Depending on the SCL, an inbound message may be relayed directly to the user’s Junk Email folder. On outbound messages, if the SCL indicates that a message is spam, it isn’t delivered, and the sender should receive a message, called a delivery status notification (DSN), telling them that the message couldn’t be delivered.
Note Everyone in your organization can use delivery reports in Outlook Web App to check the delivery status of messages they’ve sent or received. For example, if someone has sent a message to five people, they can check the status of the delivery of that message to each person. When people need more help troubleshooting email delivery, they can send the delivery report to their admin to troubleshoot using the message trace tool in the Exchange admin center.
How can individual users manage spam?
Users can manage some spam settings for their own mailbox, using Outlook or Outlook Web App.
Things to know about bulk mailings and spam filtering
- Inbound email You may find that some bulk mailings, like email newsletters you subscribe to, or notifications from large companies or social networking sites, end up in your Junk Email folder. If you want those messages to be delivered to your inbox, make sure to add the senders to your Safe Senders List in Outlook or Outlook Web App.
- Outbound email To prevent outbound spamming, the service monitors the volume of outbound mail per connection and throttles the connection when it detects suspicious outbound mail volumes. If you want to send a message to a lot of users or external contacts at once, remember that only 100 messages are accepted per connection. The best way to send messages to a large group of people is to use distribution groups stored in the shared address book for your organization. The distribution group is treated as a single recipient.
How does virus protection work?
Exchange Online Protection combats malware, including viruses and spyware. Viruses infect other programs and data, and they spread throughout your computer looking for programs to infect. Spyware refers to malware that gathers your personal information, such as sign-in information and personal data, and sends it back to its author.
The EOP service offers multi-layered malware protection that’s designed to catch all known malware traveling in to and out from your organization. To learn more, see Anti-malware protection.