Domain reputation blocks at Gmail are more common nowadays than in years past.
Suggestions: Make sure all mail passes SPF and DKIM, especially DKIM. Has to be a DKIM signature for dnn.de, not the default "onmicrosoft.com" domain that O365 will use by default. Submit a request for reconsideration here: https://support.google.com/mail/contact/gmail_bulk_sender_escalation?visit_id=638269633865177067-1793378121&rd=1 Learn more about that form here: https://www.spamresource.com/2022/01/gmails-sender-contact-form-what-and-why.html If MS is using IPv6 to send the mail to Google, you might be in an extra difficult spot. Not everybody agrees/believes this, but in my experience Gmail is more quick to block IPv6-sent mail; they're more stringent about what they might let through versus IPv4. I can't imagine that's something you can control, but, hey, if I'm wrong and it is, it's worth checking. You're on the right path with GPT. Might also want to make sure you've got a DMARC policy in place with p=quarantine or reject. If you really have no bad history with this domain, it could just be that Gmail is suspicious given a lack of history. If you REALLY get nowhere, it might be time to consider moving off of O365 and onto some other infrastructure for corporate mail. Just because you don't really have enough control over the infrastructure levers here. Cheers, Al Iverson On Sun, Aug 6, 2023 at 12:02 PM Oliver Kirchel via mailop <mailop@mailop.org> wrote: > > Hello, > > I am a postmaster for a German media company and for the last three weeks I > have had the problem that emails from a certain domain (dnn.de - hosted at > O365) are being rejected by Google (suspects your message is spam and > rejected it). Emails from the domain that are not sent via the O365 > infrastructure arrive. I then configured the domain at > https://postmaster.google.com/ and the statistics I see there actually look > quite good. Has anyone else had such an experience or is there someone from > Google reading this who I can talk/write to? > > Thanks Olli > _______________________________________________ > mailop mailing list > mailop@mailop.org > https://list.mailop.org/listinfo/mailop -- Al Iverson / Deliverability blogging at https://www.spamresource.com Subscribe to the weekly newsletter at https://ml.spamresource.com DNS Tools: https://xnnd.com / (312) 725-0130 / Chicago (Central Time) _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
