Microsoft cancels plans to rate limit Exchange Online bulk emails

Key Points:

• Microsoft has canceled its plans to implement a daily limit of 2,000 external recipients for Exchange Online bulk email senders, which was initially set to combat spam.
• The decision follows customer feedback indicating that the limit would create operational challenges, while existing recipient limits of 10,000 per account and 5,000 per tenant remain unchanged.
• Organizations should continue to implement email authentication protocols like SPF, DKIM, and DMARC to enhance security and comply with evolving guidelines from both Microsoft and Google.

Technical Details: The original plan included a Mailbox External Recipient Rate Limit aimed at preventing resource abuse in Exchange Online. Although canceled, existing limits will still apply.

MITRE ATT&CK Techniques: None mentioned

IOCs Mentioned: None mentioned