"gmail.com suspects your message is spam and rejected it."

Question

Hi,

 

This week we are experiencing a critical issue where emails sent from our Outlook/Exchange environment to @gmail.com addresses are being rejected with the following error:

 

"gmail.com suspects your message is spam and rejected it."

 

This is causing significant communication problems.

 

This happens with all Gmail recipients.

The email content does not include any links, images, or promotional language. 

This is a problem for when sending emails in bulk aswells as for emails to a single recipiant.

 

I have ensured that our domain has SPF, DKIM, and DMARC correctly configured.

Thank you for your promt reply.

Best regards

[Moderator note: personal info removed]

 

Answer 1

Please note that our forum is a public platform, and we will modify your question to hide your personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data. 

Hi @Rebecca Svenhag

Thank you for posting your question in the Microsoft Q&A forum.  

I understand that you are encountering an issue when sending emails from your business account to gmail.com account recipients.

As your description, looks like your email server's IP address has likely been flagged or blacklisted by Google's spam filters due to the unauthorized bulk sending. Gmail doesn't directly "block" IPs but uses sophisticated spam detection that can route emails to spam folders or reject them based on reputation. Since other domains work fine, this is likely specific to Google's filters. 

First could you try to check blacklists. Verify if your server's IP is listed on public blacklists, which Gmail references. Use free tools like: 

MX Toolbox (mxtoolbox.com): Enter your IP and check for blacklisting. 

Spamhaus (spamhaus.org): Look up your IP. 

If listed, follow their delisting procedures 

Next, submit a delivery issue report to Google, you can try Troubleshooting for senders with email delivery issues. 

Note: This information is provided as a convenience to you. These sites are not controlled by Microsoft, and Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. Please ensure that you fully understand the risks before using any suggestions from the above link. 

Apologies for redirecting you to the related development team support as the moderators in this community have limited resources to check the backend information, and to get the fast and better assistance we requested for it. 

I hope this helps. 

Please feel free to correct me if I misunderstood your request. If you have any additional concerns, feel free to comment below. I would be more than happy to assist. 

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Answer 2

It is not even possible sening a single email containg only text "test" to an gmail.com email adress.