Hi, using Exchange 365 and GMAIL is bouncing all emails -- unsolicited email from your IP address

Benjamin, thank you very much for your tech advice. Me and this tech person we have will try the DMARC and DMIK update.

Thanks for replying with a possible solution, it helps all of us out.

This is my first MS Community ticket.

I will let you know on this thread if it works.\

Thanks again, Bill G.

We are testing this here this afternoon so hopefully it will come good.

Interestingly I had just got onto this via a different method, because there is a message in one of the tenants that has reported this problem to us as follows:

Title: Reminder to authenticate outbound email with SPF, DKIM, and DMARC

User impact: If your organization hasn't already taken action, bulk messages sent with large BCC recipients may be rejected.

Current status: Based on customer feedback, we've refined our messaging to better reflect that we've learned of multiple email providers (Gmail, Yahoo, and others) rejecting bulk email sent from Microsoft 365 for some organizations, though not necessarily from your organization. This is a reminder that to increase deliverability of legitimate email to external recipients, it is important to authenticate your outbound emails. Information on how you can get started with email authentication in Microsoft 365 can be found in the corresponding link listed in the Additional diagnostics section of this message. Additionally, the non-delivery reports (NDRs) from these providers include details and best practices on how to deliver email to them. Please remember that Microsoft 365 is not to be used for bulk email relay, but in case the receiving email providers perceive your email as such, please read the limitations and guidelines for outbound spam protection listed in the Additional diagnostics section of this message.

It claims it will help those who are sending "a large rate or volume of email" - but in my testing it is genuinely only 2 or 3 on the CC or BCC line, or in our case via a distribution group, that has been triggering the NDRs.

So hopefully this will fix it. It's quite an escalation really, as Gmail only earlier this year finally required an SPF record... and all of a sudden they now seem to want DKIM and DMARC too.

Thanks Benjamin, this is very helpful! But like Bob, I have no idea where/what to do. I'm a bit younger, but self-employed and this basically grinds my work to a halt.

If my domain was purchased through register.com but its hosted by O365 (meaning I do not even have a website, I use ( and I'm the admin) O365 for email & office), do I look for the dns hosting settings on O365 or register.com?

Thanks!

Hi Bob,

This will not solve the issue we're all facing, but has to be checked too. Pretty sure error is related to spf record ?

If you can put a screenshot (use cut-tool : windows key => search for snipping tool, to hide personal information)

You will have to add the txt record for Dmarc & CNAME records for DMIK. Idk if your domain is directly hosted by microsoft or by an external provider.

If it's hosted by microsoft, you can add them directly in O365, if not: you're domain is hosted by an external provider, you may have access to the hosting settings or maybe not. If you do not have access to dns hosting settings, you will have to contact your provider to add those records.

Btw: this has nothing to do with age, If you're 80 and using O365 Admin, that's amazing ! Dmarc a DMIK are relatively unknown for most of the people... But to prevent the spam problems in the world, they have to activate new verifications / security.

Kind Regards,

Benjamin.

Thank you Benjamin. I just found some of this on my 365 Admin Center. I feel like Im entering the dark web with some of this stuff. At 80 I dont know how much more I can learn. I noticed that my DNS TXT and CNAME have errors and need fixing. Is this a possible cause of the problem also?