Security News > 2024 > April > Microsoft will limit Exchange Online bulk emails to fight spam

Microsoft has announced plans to fight spam by imposing a daily Exchange Online bulk email limit of 2,000 external recipients starting January 2025.
Exchange Online doesn't support sending bulk or high volumes of emails from a single account, and until now, Microsoft has not placed any restrictions on bulk emails.
With its plans for new External Recipient Rate limits, the company wants to prevent customers from abusing Exchange Online resources and restricting unfair usage.
"Exchange Online enforces a Recipient Rate limit of 10,000 recipients. The 2,000 ERR limit will become a sub-limit within this 10,000 Recipient Rate limit," the Exchange Team said on Monday.
Exchange Online customers with cloud-hosted mailboxes who need to exceed the ERR limit will have to switch to Azure Communication Services for Email, a service specifically designed for business-to-consumer communication via high-volume email sent to external recipients.
Starting April 1st, Google has also implemented stricter spam thresholds and authentication guidelines for bulk email senders to strengthen defenses against spam and phishing attacks.
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