Outgoing Office 365 (Business) Email Flagged As Spam (SCL:5)

Hello Olliedc,

Thanks for your post in the forum. Based on the information you provided, the affected senders may be considered as sending many spam emails so that the SCL will be set as 5.

To avoid it, you can try the following 2 methods:

1. Configure the spam filter policies and add the affected senders to the allow list.

2. Use mail flow rules to set the spam confidence level (SCL) in messages. Set SCL as 0 via Mail Flow rules or bypass the spam filter for internal emails, so that the message will not be marked as junk emails.

Regards,

Rick

Hello Olliedc,

May I know if you need more help on it?

Regards,

Rick

Hi Rick

The problem is that these users are NOT sending spam so therefore it's not right that their emails are often (but not always) being classified with SCL5.  Changing the settings you have mentioned will stop their emails being identified internally as spam, but will surely not help the deliverability of their emails externally as the emails will still presumably be routed through the higher risk delivery pool mail servers;  the only net result is we wouldn't know if the user's accounts were compromised and used to send spam until they reached the level of being suspended!

As I said before, it's highly frustrating that legitimate business emails are being flagged as spam in this way, yet repeated phishing emails purporting to be from Microsoft coming into the Office tenancy from outside are not being correctly identified as phishing/spam, and are ending up in user's inboxes.  With the latter we can obviously employ a more advanced third party anti-phishing solution, but you would think EOP would at least be better at filtering out fake "Microsoft" emails, seeing how it generates so many false positives on outgoing emails.

Can we report these outgoing emails anywhere with a vain hope that the outgoing spam detection can be improved to stop identifying these genuine emails as spam?  Or perhaps you can advise another reason why the emails are being identified as such.

Many thanks 

Hello Olliedc,

In order to investigate to the issue further and figure why the message is marked as spam, I want to collect the affected message’s entire mail header. Please double-click an email message to open it outside of the Reading Pane. Click File > Properties. Header information appears in the Internet headers box.

Please upload some mail headers and the tenant information via private message.

Regards,

Rick

Hello Olliedc,

Do you need more help on it? 

Regards,

Rick

Many thanks, I've just now replied with a PM with the requested details.

Kind regards

Hello Olliedc,

I have checked your private message and here is what I found: The emails are marked as spam because of the EOP spam filter. Also, I found the sender’s IPs are blacklisted by third-party blacklists.

The possible reason is that the emails are marked as spam by EOP by false. Due to privacy, I have replied you via private message. Please check my reply for the following step.

Regards,

Rick