Outlook takes a number of factors into consideration before placing a message into the Junk Email folder.

• Outlook checks if a message is on your Blocked Senders list or Safe Senders list. These lists are configurable through the Outlook Junk Email Options.
• Outlook will consider the contents of the message, much like other email security systems do.
• See the Managing your Junk Email Folder for tutorials for more details
  • Managing your Junk Folder in Outlook 2015/2016 (Mac)
  • Managing your Junk Folder in Outlook 2013/2016 (Windows)

When Microsoft determines that a piece of email may contain a security risk, that email is placed in the Junk Email folder.  All functionality of the email is disabled - such as links - to prevent anything from happening if you inadvertently open the email.

This default folder is used to save messages marked as junk email by the Exchange Online Protection or by the anti-spam filter in Outlook. The retention for this folder is set to 30 days and cannot be modified. Users should check their Junk folder at least once a month and move emails they deem "not junk" out of the folder before they expire and are removed. Once an email is deleted from the Junk Email folder, it is not recoverable.

Microsoft is very good and have many resources to determine just what should be put in your Junk Email folder, but sometimes they will still end up in your Inbox.  If you receive an email that you are not expecting, or from someone you do not know - be cautious. If your curiosity gets the better of you and you need to open the email move it to your Junk Email folder.  At least then links and any "bad" content will be filtered out of the email.  If it turns out to be valid you can move it back to your inbox.

Since Microsoft analyzes where an email is from as well as what the email contains,  it is possible that something within the email could trigger a positive "junk" tag. In this case, you can:

• Move the email back to your inbox; 
• Choose to never block that sender; or 
• Add that sender to a safe senders list or a  white list.

If Outlook places a message in your Junk Email folder, but you know the sender and believe it is safe to open, you can move the message back to your Inbox.  All functionality of the message will be restored and you will be able to open it. Right mouse click on the message and select Mark as not Junk.  The email will be returned to your inbox and all functionality will be returned.  If you are unsure if the email is safe, you can open it in the Junk folder.  Microsoft will have neutralized any bad content - including links.

There is always the chance that an email will be placed in the Junk Email folder because it fits Microsoft's criteria.  Items like newsletters or magazines that you have subscribed to are more likely to trigger a False Positive. If you are certain that a message in the Junk Email folder is something that you really do want, you can move it back to your Inbox by right clicking on the email and selecting mark as not junk.

Although it is possible to build a Safe Senders list in Outlook Web, the easiest way to do it is using the Outlook 2016 desktop client.

• Navigate to the Junk Email folder in Outlook 2016.
• Right-Click on a message that you want to add to your Safe Senders list.
• From the drop down list of options, select Junk.
• From the Junk drop down list, select Never Block Sender. You will receive a pop up message that states The sender of the selected message has been added to your Safe Senders List.
• Click OK.

Email messages from this sender should now be delivered directly to your Inbox. Please be aware that some marketing firms send messages out from more than one account, and therefore it may appear that a message you have added to your Safe Senders list is still being blocked. If this happens, simply follow the same procedure as listed above for adding a sender to your Safe Senders list.

Using Outlook Web, you can right-click on a message in the Junk Email folder and select the option from the drop down menu mark as not junk. This will move the message from your Junk Email folder and place it in your Inbox. This does not add the sender to the Safe Senders list.

To add a sender to the Safe Senders list, you must do the following:

• Click on the settings gear in the upper right corner of the Outlook Web window, next to your name.
• Select Mail under Your App Settings.
• On the left side of the Options window, click on block or allow.
• In the block or allow window, you will see a safe senders and recipients list and a blocked senders list.
• In the appropriate list, type in the email address you are wanting to block or allow and click the plus (+) sign.
• When you are done adding senders to the appropriate list, click save.
• To return to your email boxes, click the arrow located on the left side of the window, just above the word options