Experiencing Rate Limits When Sending Emails to Outlook Domains?

Yeah, I've been experiencing the same issue since yesterday! Emails to all the Outlook domains are getting deferred, and I can't seem to get anything through. I also have several different IPs for outgoing SMTP, but they might be at risk too since I’ve queued up hundreds of messages since the rate limit started. It's really frustrating! Glad to know I'm not alone in this.

Yeah, I’ve been looking into it too! Not just Sendgrid, but even services like MXroute and Mailgun are facing significant delivery hurdles. Some users have managed to find workarounds by switching outgoing SMTP IPs. If you haven't already, it might be worth trying that to clear out your message queue.

We’re having major issues as well with our IPs being temporarily rate limited. We send a lot of emails through Sendgrid, and since the 24th, we haven’t been able to deliver anything to Outlook domains. It's a big problem for us because about 30k of our 100k emails go to those addresses every month.

I think it's really a widespread issue. A lot of us here are reporting similar problems with different email service providers. Some folks have even tried contacting Microsoft support, but it seems like they’re just getting auto-responses. I think groups are forming in various threads to get Microsoft’s attention on this.

I've seen the same rates going on for a while now. I even opened a support ticket with Barracuda and they confirmed that Microsoft is behind this issue. They suggested a temporary solution to bypass their email gateway defense, which looks like a way to restore normal mail flow. Good luck to everyone!