This is really bad - cloudflare seems way too quiet on this ongoing majorly disruptive issue.
Even trying to register to use this forum was almost impossible:
Have a 75% failure rate in the last 24 hours, week and 2 weeks consistently for my family’s email addresses due to this issue.
n/a
upstream (587659990.pamx1.hotmail.com.) error: failed to initalize: Unknown error: permanent error (550): 5.7.1 Unfortunately, messages from [104.30.8.75] weren’t sent. Please contact your Internet service provider since part of their network is on our block list (S3150). You can also refer your provider to Troubleshooting. [Name=Protocol Filter Agent][AGT=PFA][MxId=11B9A2E5FF64207C] [AMS0EPF000001AE.eurprd05.prod.outlook.com 2024-10-09T11:23:53.774Z 08DCD1732B57F9AD]
Mail forwarding is being marked as failed delivery because Microsoft is blocking some Cloudflare IP addresses.
Reached out to Microsoft, they said Cloudflare must contact them.
Same issue here:
Also have 75% failure rate consistently in the last 24 hours, week and 2 weeks (maybe they only block 75% of servers) 
Same, just bumping wishing for a fix.
How is Cloudflare not updating us or addressing this issue with msft?!
I suggest people stop posting their domains, Cloudflare are not checking this thread, all you are doing is opening your domain up to potential attack or spam.
For those still experiencing issues, I suggest you move your routing services elsewhere, as some of us did last week and have been fine since. I’m now paying for a service but it’s not expensive compared to Cloudflare’s packages. I wonder if premium tiers are also affected…
Any services you’d recommend that can work with outlook.com?
@gcg5: ANY full-service email solution that’s properly configured should work with Outlook.
Just stay away from any free-for-all (including spammers) email forwarding service, irrespective of who the provider is… if your emails and time are worth more than $5 a month (which is how much professional email solutions like Google Workspace, Microsoft365, Zoho Mail, etc cost).
Hello everyone,
in the last few days, I’ve been experiencing issues with the email routing function towards Outlook live mail.
From the dashboard, I see the following error:
upstream (eur.olc.protection.outlook.com) error: failed to initialize: Unknown error: permanent error (550): 5.7.1 Unfortunately, messages from [104.30.10.104] weren’t sent. Please contact your Internet service provider since part of their network is on our block list (S3150).
It seems that Outlook is rejecting the emails routed to them.
The function I am using is the ‘email routing’ feature within the dashboard.
Have any of you encountered this issue as well? Is there a way to resolve it?
I’m also getting this. Only noticed it due to a specific email not being received. Looks like its been happening for a few days so likely some emails are now being lost for good. I get outlook has blocked cloudflare but surely CF should put some sort of status up considering how much of an impact it could be. Also realised that they can’t have monitoring on it as i’ve got from a healthy status of emails to less than 4% being forwarded! Temporary solution has been to forward to another email I have.
The wrinkle is working with outlook web client / office365 family… I’ve had this setup, working, and familiar to my family for VERY long… Would any of the namecheap/hostgator/etc… solutions work with outlook webmail / office365 family (with IMAP/POP setup, obviously) to your knowledge?
I do enough technology onboarding/training at work… trying to minimize it at home 
Thanks for the support!
I will not be sharing the service I moved to as I don’t want it to end up in the same situation. I will say there is no shortage of alternative email routing services out there, and at reasonable prices. Prices I’d have been happy to pay Cloudflare if it would guarantee service.
Cloudflare could resolve this but they also arn’t the source of the problem - the real problem is spammers abusing Cloudflare’s free services. Both are guilty though, Cloudflare should be doing something to prevent it or offer more realistic pricing plans (I’m not gonna pay for full services when I only need DNS and email routing…)
I was a big fan of Cloudflare before this but I’ll be using it for DNS and nothing else now. I’ll eventually move that too.
Try add/modify spf:
v=spf1 include:spf-a.outlook.com include:spf-b.outlook.com ip4:157.55.9.128/25 include:spf.protection.outlook.com include:spf-a.hotmail.com include:_spf-ssg-b.microsoft.com include:_spf-ssg-c.microsoft.com ~all
after spf1 leave default entry for e.g. include:_spf.mx.cloudflare.net
use mxtoolbox.com to check spf configuration for your email provider.
550
Unfortunately, messages from [104.30.6.54] weren’t sent. Please contact your Internet service provider since part of their network is on our block list (S3150)
The IP address 104.30.6.199 g-bjj.cloudflare-email.org is on Outlook’s block list
No steps I can take other than reporting this
Email relayed via Cloudflare is not delivered to Outlook
v=spf1 include:_spf.mx.cloudflare.net include:spf-a.outlook.com include:spf-b.outlook.com ip4:157.55.9.128/25 include:spf.protection.outlook.com include:spf-a.hotmail.com include:_spf-ssg-b.microsoft.com include:_spf-ssg-c.microsoft.com ~all
Did this work for you and email is flowing via Cloudflare to Outlook.com for you now? Thanks
Yes, seems that now is working fine from 2 days after SPF modification. I bought pro support and cloudflare support still didn’t help.
Thanks for the tip, I will try this! I also have the Pro plan but never get an update or reply from them on a ticket.
Buying a Pro plan and also getting zero response from Cloudflare - please tell me you have learned lessons and are moving away from Cloudflare?
Very unprofessional approach on their part
