Why is Microsoft temporarily rate limiting emails due to IP/URL reputation?

Email marketer from Email Marketing Forum mentions that they had issues with Microsoft because their domain was newly registered. Microsoft's filtering can be stricter for new domains until they establish a good reputation.

Email marketer from GlockApps suggests actively monitoring blocklists, explaining that if your IP or domain ends up on a blocklist, Microsoft is highly likely to rate limit or block your emails.

Email marketer from Litmus discusses that Microsoft often uses engagement as a primary signal for filtering. If users consistently ignore or mark your emails as spam, your sender reputation suffers, leading to throttling.

Email marketer from Email Geeks shares context that they observed low deferral rates from Microsoft on their own IPs. However, a client sending a link from their own ESP experienced high deferral rates to Microsoft for over a day, suggesting a combination of URL and IP reputation issues.

Email marketer from StackOverflow mentions that URL shorteners can sometimes negatively affect URL reputation. Microsoft might flag shortened URLs more readily because they can mask the true destination.

Email marketer from SendGrid explains that the reputation of URLs included in your emails can significantly impact deliverability. If a URL is associated with phishing or malware, Microsoft is likely to rate limit or block the email.

Email marketer from Reddit shares that Microsoft is aggressive with its rate limiting and filtering. They advise monitoring your IP and domain reputation, ensuring your emails are properly authenticated (SPF, DKIM, DMARC), and engaging in list cleaning.

Email marketer from Email on Acid discusses that Microsoft's filtering algorithms consider various factors, including sender reputation, content, and engagement. If your emails are not engaging users, they might be marked as spam or throttled.

Email marketer from Mailjet explains that a poor IP reputation can trigger Microsoft's rate limiting. This can be due to sending spam, having a low engagement rate, or being listed on blocklists.

Email marketer from GMass mentions that your sender reputation is crucial for deliverability. Microsoft is more likely to trust senders with a good reputation, which can be built through consistent sending practices and positive engagement.

Expert from Email Geeks shares their experience of seeing the same error for one client but not another on the same IP. While acknowledging it could be IP reputation, they suggest it might also be a message-specific bounce from Microsoft.

Expert from Word to the Wise explains that Microsoft places a high value on user engagement. If recipients rarely open or interact with emails from a particular sender, it can negatively impact sender reputation and lead to rate limiting.

Expert from Email Geeks suspects the issue to be related to URL reputation, saying they've experienced similar bounces in similar situations.

Expert from Spam Resource mentions that Microsoft can be particularly sensitive to URL shorteners. As URL shorteners can be used to mask the true destination, Microsoft may penalize emails containing them, especially from senders with lower reputations.

Expert from Spam Resource explains that Microsoft is known to heavily weigh sender reputation. They actively use reputation metrics to determine whether to accept, rate limit, or block incoming emails.

Expert from Word to the Wise explains that Microsoft's SmartScreen filter evaluates the reputation of the sending IP address and domain to determine whether the email is likely to be spam. A low reputation can trigger rate limiting.

Documentation from SparkPost explains that Microsoft, like many email providers, uses rate limiting as a mechanism to protect their infrastructure and users from spam. If your sending IP or the URLs in your emails have a poor reputation, you are more likely to be rate limited.

Documentation from Microsoft Learn explains that Microsoft uses IP reputation as one factor in determining whether to accept email from a particular source. Poor IP reputation can lead to temporary rate limiting or blocking.

Documentation from Microsoft Security Blog explains that Microsoft Defender for Office 365 scans URLs in emails for malicious content. If a URL is flagged as malicious, emails containing that URL may be rate limited or blocked to protect users.

Documentation from Cisco Talos explains that reputation filters evaluate both IP and domain reputations. Microsoft utilizes these filters to identify potentially malicious senders and URLs, leading to rate limiting or blocking.