Office 365 Internal Mail Marked as Spam Problem

Anuraag Singh | January 16th, 2018 | Updates

Are you facing the issue of Office 365 emails going to Junk folder or Office 365 internal mail marked as spam automatically? Don’t worry!

Like every other mode of communication, emails are also not free from unwanted intrusion. As the counterpart of unwanted and marketing calls, we have spam or junk emails. Luckily for us, every email client has a spam or junk folder where they put unwanted emails. Junk folder can also be a source of problem when normal emails start going to it. Here, we will discuss the problem of Office 365 emails going to spam folder and ways to take them out. First, let us go through some user queries regarding this issue:

Query 1: “We use Outlook Office 365 in our University as official email. For last few days, I was not receiving any emails. When I personally contacted my supervisor, he told me that he had sent me 4/5 emails but got no reply. Hearing this, I checked my junk folder and saw all emails going to Junk folder in Office 365. I was wondering what led to this situation. I have obviously not marked his emails as junk before. That day I have marked his emails as ‘Not Spam’ but it is not working. I still have to check my junk folder to get his emails. Please help so that my Office 365 email going to junk folder could be stopped.”

Query 2: “From last month, installment payment reminder mail from my bank is going to junk folder of Office 365 email. For this reasons I almost missed my last installment because of the issue of Office 365 internal mail marked as spam issue. To avoid the same situation this month, I have included that id into safe senders list. Unfortunately for me, this method did not work. Even this month, that mail went to the Junk folder. Can anyone tell me how to stop this false positive action from Office 365 so that my Office 365 email marked as spam problem?”

Quick Hack TipExport Office 365 mailbox to PST and get backup of all Exchange Online email data and prevent data loss in your Office 365 account.

Problem: Legitimate Emails going to Junk folder

Having legitimate emails going to Junk folder is no less annoying than having spam email in your Inbox. Have a look at the reasons behind this problem briefly and then move to solution part. This issue occurs when Office 365 considers emails from trusted sources as spam. This results in legitimate emails ending up in Junk folder. During this situation, users have to check junk folder to see if it contains any legitimate emails. To get rid of this problem, users can apply these techniques.

Manual Methods to Stop Emails Going to Spam Folder

There are a number of ways to stop legitimate emails going to Junk. In this segment, readers will learn these methods.
1. Configure Spam Filter Policy: First, users should verify ‘Advanced Spam Filter’ policies to check if an entire domain has been blocked. If yes, then all emails coming from that particular domain will go to Junk. Users can disable advanced spam filtering options that cause such problem. Users can also create ‘Safe Senders List’ in Office 365 by going to Settings>> Options>> Block or Allow. Note that Exchange Online Protection (EOP) does not keep track of domains. It keeps only senders and recipients.
2. Using Directory Synchronization: This technique is applicable only to the Exchange Online users. Usually, Office 365 email users are by default protected by Exchange Online Protection (EOP). In case of EOP-only subscribers, they can use director synchronization to fix this problem. Directory synchronization allows users to synchronize their own settings with EOP services. Thus EOP will have access to user’s ‘Safe Senders List’ and function accordingly.
3. Setting Connection Filter’s IP Allow list: To fix false negative issue of Office 365 emails to Junk, users can add senders’ IP addresses to IP allow list of connection filter. When users enable ‘Safe List Only’ option, they receive emails sent by the enlisted senders only to their inbox. In this case, adding IP address cannot eliminate the problem of Office 365 email marked as spam completely.

How to add an IP address to IP Allow list of Connection Filter

  • By extracting header of emails sent by preferred senders from Outlook or OWA.
  • By following the manual in ‘Use the EAC to change the default connection filter policy.’
  • By manually finding IP address with Message Analyzer tab of Remote Connectivity. Analyzer. Users can also use CIP tag of X-Forefront-Antispam-Report header.

4. Verifying Junk Email Setting: Users can execute the below command to check the configuration setting of junk mail.


  • If the TrustedListsOnly value is true, the setting is enabled.
  • If the ContactsTrusted value is true, user trusts both Contacts and Safe Senders.
  • TrustedSendersAndDomains value shows contents of the user’s Safe Senders Lists.

5. Using Safe Senders List: Web Outlook users can use this method to stop emails from ending up in Junk folder. If there is a message with yellow colored safety tip, it means the email is in the junk folder. Users can check the header of email whether it still contains SFV:SKN or SFV:NSPM stamp. It happens because Outlook ‘Safe Lists Only’ setting overrides the EOP setting. In case emails are going to junk folder irrespective of marking, turn off the option ‘Safe Lists Only’.


Office 365 emails going to junk folder is surely a serious problem for O365 users. This hampers user productivity and makes O365 email usage irritating. We have discussed several solutions to resolve this problem. Users can implement these techniques to fix O365 mails going to Junk folder & stop legitimate emails going to junk folder.