messg spam from my office email to yahoo

Occasional Visitor

when i send a mesg from my office to yahoo , the message enter to inbox folder , then after 1min  or 2min , the message fall to junk folder , can someone help me with this , or explain to me what going on

95 Replies
Our tenants have also been having an issue with Yahoo and AOL addresses. As of today, Hotmail addresses now seem to be an issue too. Looking at Glock Apps deliveribility reports confirms there's issues with outlook/hotmail addresses. Only unaffected "well known" address is gmail at this time. I have also logged a case with Microsoft to investigate, everything is pointing to their IP ranges finding their way on to a one or more blacklists.



This is the same message I received. I waited the "several days" and nothing has changed.


Unfortunately, Yahoo's suggestion that we contact thousands of clients and tell them to look in their Spam folder and mark our mail as "Not Spam" is not an option... especially when often our primary form of contact is by email.

@nstclairz In addition to that, marking a message as not spam does not mean that it will no longer be sent to the spam folder. It just sends a message to the postmasters. A few hours later, a message delivered from the same e-mail address to the same Yahoo address will go to the spam folder. The only resolution that I could find is to add that e-mail to contacts in Yahoo. Filtering does not work since Spam filters work before the user filters.

We are having this issue as well with one of our O365 tenants that send email to end users, many of the recipients have accounts.  In testing, i created a brand new email account and sent email to it from 3 different Microsoft O365 tenants, all 3 emails went directly to spam folder.  Then i sent mail to this brand new account from an aol address and gmail an they went to the inbox.  This tells me Yahoo is definitely filtering Microsoft mail directly to spam since this was a brand new email account.  When i run the headers for the email i sent from Microsoft accounts through mxtoolbox header analyzer, all checks are perfect, spf, dmarc, dkim pass so i know there is nothing wrong with the configuratin.  Does yahoo have any checks to run the headers through so you know why they are labeling the mail as spam?  So are people opening tickets with Microsoft because you think their sending IP's are on blacklists? Curious as to why more people are not opening tickets with Yahoo... Since these are free accounts, will Yahoo even do anything? I couldnt find where to open a ticket with Yahoo... 

I did some quick testing on Hotmail and accounts. I got mixed results- my fully setup corporate tenant sent the mail fine to my Inbox at both Hotmail and, however, my other personal and test tenants delivered the mail to the Junk Email folder at both and One of my tests from a specific tenant went to junk the first time and to my inbox the second time.

This is concerning, as it lends some credibility to Microsoft's culpability here- at least partially.

That's the problem with AOL/Yahoo- there is no free support, you need to sign up for a subscription for any sort of support. A poster on here did that and got nowhere (yet) unfortunately.

Some of us have tried submitting tickets here:

Thanks, i just tried to put in a support ticket using the link you provided but it seemed to go to a black hole, i didn't get an auto response. One thing I noticed from running my headers through mxtoolbox header analyzer, it passed all dkim, dmarc, spf checks however it did show the sending server has an ipv6 IP showing therefore listing it on a blacklist called CYMRU BOGONS IPv6. Has anyone else seen this if you run the headers through mxtoolbox? It looks like all 3 of the tests i sent from 3 different Microsoft O365 tenants show this blacklist when running the headers through through mxtoolboxes header analyzer.

@Amber Yes, we're exactly the same.

i just got this response from Yahoo.

Thank you for contacting Yahoo Postmaster.

I understand that your emails are incorrectly delivered to the customer's spam folder. I know how inconvenient it is to you. I'm happy to help.
I've reviewed your case and recently you may have noticed an increase in mail going to the spam folder for senders using Office 365 and other Microsoft products. We are in the process of addressing this issue and expect it to improve over the next several days. Please have your recipients mark the mail in the spam folder as “not spam” or “ham” and that will help to correct the issue. Thanks for your patience.
I hope you find this information useful. Do not hesitate to reach out to us if you have any other questions!


Yahoo Postmaster
I am seeing the same thing on my test emails with the same blocklist. I've forwarded the headers to my open ticket with Microsoft, we'll see if anything comes of it.



Thank you for the response. We also have cases opened with our CSP and Yahoo support. I'm in the process of sending headers of one of the spam messages to Yahoo support and reiterating that the issue is not isolated.



Hello, yahoo635. Here is a quick solution for such cases:


Go to Yahoo Mail and your account and check the folder with the name "Spam". Hit on the email wrongly marked by Yahoo as junk and open it.


Check it with the "Not Spam" button, and this will send the email back to the inbox. The sender is verified and will never be treated as a spammer in your mailbox.


Still, if you use the account for work, I would recommend better using Microsoft 365 Outlook + NAKIVO backup for Microsoft Office 365 to boost your organization's data safety and recoverability.

That is a good step to take, but doesn't solve the problem. The next email will still be in spam.

I'm afraid you're not actually pushing a solution, but instead a place you can paste your link that is not related to this problem at all.

As a reminder, please refrain from posting third-party links.




Office 365 Community Manager and 

Tech Community Admin

@yahoo635 Adding my voice to the thread as we have the same issue. Interestingly, my wife and I both work at the same company but her free version of Yahoo mail receives work O365 emails fine, but my Yahoo Plus flags them all as spam.


This has only started happening recently, but when I run a recent spam email and an older non-spam email through '' they both get flagged as failing the 'SPF Authenticated' section due to a null DNS lookup.

I've been testing this pretty much every day with no change. Today when I sent to Yahoo it goes to Inbox. But when sent to AOL, it's still going to the spam folder.

What we ended up doing is using a third party spam service we have as a smart host and that puts the messages back in inbox.  

@dketterer1 Yes, same here: Yahoo delivered to inbox. Progress!


I mentioned previously that my wife's free Yahoo email worked, but that wasn't 100% true: it delivered the message to the inbox but when she opened it, it was flagged as spam but said it delivered it anyway as I was a known contact.

Still broken, test done 5 minutes ago from different office 365 tenants. Same result.




I've been having this issue as well. I've tested with a friend that uses Yahoo and my own yahoo account. Happened as of a few minutes ago—my secondary domain was moved from Google Workplace and it's now happening with that one too (well, it's going to the inbox since it has a history with my friend, but it's still being flagged as spam for him; just not put in the spam folder).