Spam still going to junk email folder despite anti-spam policy

Question

Hi Guys,

I'm trying to configure the default inbound anti-spam policy in Exchange Online Protection (now under Microsoft 365 Defender / security.microsoft.com) to allow all spam through and only block phishing attempts. We do this by setting the "Spam" and "High confidence spam" actions to either "Add X-Header", or "Prepend subject line with text". These both work, but the problem is that emails that are classified as spam are still going into the user "Junk email" folder.

Does anyone know how to prevent this? There's a seperate action called "Move message to Junk Email folder" but we're not using that. What is causing the mail to go into the junk folder. I've checked the Outlook client settings and they're set not to do any spam filtering.

Any help would be much appreciated, otherwise I'll have to go through the rigmarole of engaging Microsoft support.

Cheers

Answer 1

Run a message trace against one of the offending messages, see what the details therein show. It will give you an idea whether the "move" action happened server-side or client-side, and you can go from there.

Answer 2

Hi @Tom Wardrop ,

According to the document below, "In Exchange Online, the message is moved to the Junk Email folder if the junk email rule is enabled on the mailbox (it's enabled by default).".
Configure anti-spam policies in EOP

So I'd recommend run the command below on one user mailbox and see if junk email rule is enabled:

Get-MailboxJunkEmailConfiguration -Identity "<MailboxIdentity>" | Format-List Enabled  

If it's indeed in the enabled state, try disabling it and check the result:

Set-MailboxJunkEmailConfiguration -Identity "Ori Epstein" -Enabled $false  

If it works, you can disabling the junk email rule for all users using:

$All = Get-Mailbox -RecipientTypeDetails UserMailbox -ResultSize Unlimited; $All | foreach {Set-MailboxJunkEmailConfiguration $_.Name -Enabled $false}  

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Answer 3

Hi have the same issue, although I am not trying to disable this for the group but rather one mailbox that we rely on mails reaching the inbox to process the inbound communications and direct them correctly.

I have created a new spam filter, applied to the specific mailbox only, the rest follow the default policy. If I check via powershell it confirms that mailboxjunkemailconfiguration is set to false however mails are still being directed to junk.

Answer 4

Interesting. Stumbled upon this via a google search.

I am having the exact same issue. I have had an open ticket with 365 support since mid-November about this with no fix in sight.

We have customer anti spam policy set to only tag emails and yet EOP is still delivering emails to the junk folder.

The above Powershell commands have been confirmed to no longer have any sort of effect (but we have run them for good measure just incase to no avail).

EOP is simply ignoring the actions set and still delivering mail to the junk folder.

Answer 5

Same problem here. I use an external spam service and disabled antispam on all my mailboxes. However, Microsoft 365 / Exchange still delivers (valid) mail to my junkmail folder.

How to stop this permanently?