Microsoft Removes External Recipient Rate Limit for Exchange Online Mailboxes
Microsoft announced the indefinite cancellation of the mailbox external recipient rate limit in Exchange Online, removing the fixed cap that restricted how many external recipients a mailbox could email per day. The limit was originally introduced to reduce spam and account compromise risk, but given customer feedback, Microsoft says this no longer aligns with how organizations use email at scale. Instead, Microsoft will use smarter, less disruptive and adaptive approaches that aligns with business workflows.
The update reflects broader changes in how cloud email security is managed. As organizations automate notifications, customer communications and application-generated email, static recipient limits have increasingly conflicted with legitimate business workflows. Microsoft noted that other controls—such as spam filtering, anomalous sending detection and compromised account protections—remain in place to mitigate abuse. The core goals to mitigate abuse and prevent misuse remain the same and will continue to be present across Exchange mailboxes.
Posted by Redmondmag.com Editors on 01/07/2026