Hi all,
We have Exchange server 2019 and we configured dkim on mysmtp. Dmarc record is also created. Problem we have is that all mails are going to recipient spam folder in office 365. I am really out of ideas and need help with this.
Hi all,
We have Exchange server 2019 and we configured dkim on mysmtp. Dmarc record is also created. Problem we have is that all mails are going to recipient spam folder in office 365. I am really out of ideas and need help with this.
Hi @NT-8243
According to your description, this question seems to be related to Exchange, so we would move the irrelevant tags.
Add exchange server public IP and the domain name into o365 allowed list.
Please refer below for more details,
https://docs.microsoft.com/en-us/microsoft-365/security/office-365-security/create-safe-sender-lists-in-office-365?view=o365-worldwide
Further you can **check and control SCL leve**l. Please refer following for further details,
https://docs.microsoft.com/en-us/microsoft-365/security/office-365-security/spam-confidence-levels?view=o365-worldwide
https://docs.microsoft.com/en-us/microsoft-365/security/office-365-security/use-mail-flow-rules-to-set-the-spam-confidence-level-scl-in-messages?view=o365-worldwide
https://docs.microsoft.com/en-us/exchange/antispam-and-antimalware/antispam-protection/scl?view=exchserver-2019
Other tip is to check Domain or IP black list status. Please check the Domain/IP blacklist status which are relevant to you Exchange server.
https://mxtoolbox.com/blacklists.aspx
As Udara posts, some configuration is recipient-side.
Does your issue occur only with some specific recipients in same configuration or it has problem with most recipients when sending external?
This blog might help you and your recipient troubleshooting: http://howtomicrosoftofficetutorials.blogspot.com/2018/01/prevent-email-from-being-marked-as-spam.html
Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.
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Hi Guys,
Thank you for your reply. Keep in mind that we have exchange 2019 on prem and the emails that we send to customers that have email in office 365 goes to spam. Our dkim is on mysmtp and dmarc is configured with reject. SPF record is valid as well. I asked clients to run submission in office 365 to check the reason why our mail is classified as spam the response was almost without any info.
Rescan status - Completed
Delivery details - StatusSpam
Rescan results - Spam
Maybe I was not expressing it clearly, so again, do you have same issue with other 365 tenants?
If he is the only tenenat that blocking your messages to spam, it must be due to his particular organization configuration rather than yours.
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Hi,
95 % of all customers reporting that our mail is going to spam. When I run message trace (in 2 customers tenants), it shows Filtered as Spam (for our messages) and under Message events I see DLP rules but customers have no rules or DLP policies in the tenant. I even run submissions to see why they are filtered as spam without luck. Message trace looks like this

In addition, extended summary report shows 0 messages.
Are the rest 5% all non-O365 tenants?
Do the 95% have any third-party softwares installed? Or Exchange Online Protection Custom Malware Filter enabled?
What if your customers run "Get-DlpComplianceRule" with those rule ID?
Just a thought, could you send a blank meesage to those recipients to test if any words like sigature or such things were blocked by the default DLP rule?
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