Posted by xmddmx 20 hours ago
5.4.1 smtp; 550 5.4.1 Recipient address rejected: Access denied.
For more information see https://aka.ms/…ors
<redacted>.eurprd02.prod.outlook.com 2026-11-08T19:48:58.651Z <redacted>]https://learn.microsoft.com/en-us/troubleshoot/exchange/emai...
Some additional context:
- I checked online and they do have this email address listed on their pages
- This affected 2 separate domains served by Microsoft
- I sent them an inquiry email now from my @gmail.com and no bounce was returned so far
EDIT: Also gmail got the error response, so I guess it's really up to the outlook server these unrelated entities use...
When I see in my logs that the e-mail has been successfully delivered to their MTA then I don't have a problem.
(If this happens to you, don't admit that you know Microsoft drops your emails, or you'll be liable again!)
I had an email server and configured everything by the book. Still some scammer were able to send emails which looked like they came from me, so i got responds back.
If not even this was fixed...
> The sender gets a bounce
?
It's quiet only if the server accepts it and then deletes it on their end without notifying the sender, but if your mail provider shreds your mail that's then also your provider's responsibility and not the sender's
I had a legal dispute once where a shop didn't provide warranty on a product. They took the product in but then it was indefinitely in repair. Long story short, it ended up being helpful that I have email server logs that show every transaction, so that I could say "on date+time the email was delivered to IP address X, which was registered as the mail exchanger for your domain, and your server took the email with status code XYZ Queued <ID> For Delivery." Would have been interesting to hear what a judge has to say about it but they simply agreed to give the full purchase price back after that
Afaik that's not what Microsoft/Hotmail does though: since it rejects noncompliant setups (as well as a lot of legitimate email, unfortunately), the sender gets a delivery failure notification
Sounds like kind of a hack:
"ARC was devised to solve this problem by giving intermediate servers a way to sign the original message's validation results. Even if the SPF and DKIM validation fail, the receiving service can choose to validate the ARC chain. If it indicates that the original message passed the SPF and DKIM checks, and the only modifications were made by intermediaries trusted by the receiving service, the receiving service may choose to accept the email."
maybe someone was too lazy to set up "inbound block list" and just did a total blackout instead?
Not true, at least in my experiences.
I have a bunch of email accounts which have SPF and DKIM, but are missing the DMARC line - I've had no deliverability problems at all, until this weekend, and now only with Outlook. Emails to Gmail accounts go through just fine.
The combination of: √ Valid SPF √ Valid DKIM signature X Missing DMARC policy
Is clearly ambiguous. Since a DMARC of "p=none" (in the context of valid SPF and DKIM) really adds no information, so interpreting "missing DMARC" as "p=none" seems reasonable. Sounds like Microsoft was taking that approach until this weekend.
I wonder if there's an actual written standard?
Most receivers have chosen to treat this as p=none for the last decade (Microsoft included). This is changing to now so that mail with no record is simply refused. Nothing in the standard prohibits this.
a DMARC of p=none might be seen as ambiguous - SPF and DKIM have their own jobs and they work. However, the point of DMARC is not a new way of enforcing mail authentication. Instead it is a way of making certain that the mail is internally consistent and furthermore provides two additional things.
1. it indicates if the domain owner has thoroughly gotten their mail to authenticate (in which case they adopt a p=reject), and
2. it provides a feedback mechanism that allows the domain owner to know if they are seeing authentication and deliverability problems in such a way that they can fix those broken mail flows.
Receiving is still self hosted.