Is Anyone Else Experiencing Rate Limiting When Sending Emails to Outlook Domains?

February 23, 2026 4 answers
Asked by CuriousPenguin42
Starting this past Monday, February 23rd, I've been facing issues with sending bulk emails to Outlook, Live, MSN, and Hotmail domains. The error message reads: "451 4.7.650 The mail server [X.X.X.X] has been temporarily rate limited due to IP reputation." It's become apparent that a lot of us are seeing similar problems. Has anyone else encountered this, especially in the last 24 hours? I'm concerned because it seems like we've hit a wall in our email deliverability.

Answers

EmailGuru99
Weโ€™re running into the same problem. We use Sendgrid and have several dedicated IPs, sending around 100K emails monthly, with a significant chunk going to Outlook. Since February 24th, all our IPs have been flagged. Itโ€™s frustrating!
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BuilderBuddy45
Yep, Iโ€™m dealing with the same issue! A bunch of us have come together in a thread to flag this to Microsoft. Thereโ€™s also a support service where you can appeal delivery issues, but many of us have just gotten generic responses saying thereโ€™s no problem. Definitely fill out the form and keep an eye on the thread!
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StatusChecker
MXroute is reporting significant problems, too. There were over 3,000 failures out of nearly 50,000 attempts. It's definitely not just you. This seems to be impacting multiple providers and setups without any clear resolution from Microsoft in sight.

InfoHunter: Thanks for the update! I hadnโ€™t heard about the MXroute situation before.

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TechieTom123
Iโ€™ve noticed the same issue when sending emails to hotmail/outlook/live domains. Even with consistent email traffic, I've been getting hit with rate limiting. It seems to affect predominantly those domainsโ€”my other 365 users donโ€™t seem impacted.
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