Microsoft cancels spam protection measure in Exchange Online

Microsoft had devised a measure to protect against excessive spam: limiting the number of emails that can be sent to external recipients. Now the company announces that it will not implement the measure for now and will suspend it indefinitely.

This was announced by Microsoft in a blog post in the Techcommunity. The manufacturer cites customer feedback indicating that the limitation would bring “significant operational challenges” -- especially given the limited capabilities of current mass mailing services. Microsoft now wants to take this into account.

However, the goal remains to combat misuse of Exchange Online customers, such as spam or malicious mail activities. Furthermore, Microsoft wants to prevent misuse where, for example, industry solutions send mass emails via Exchange Online. To this end, the developers intend to devise measures that interfere less with business processes. However, the existing limits remain unaffected by this, Microsoft adds.

Rate and Recipient Limits

Originally, Microsoft announced in April 2024 that from April of this year in Exchange Online (trial versions and new tenants) and from October 2026 for all existing cloud-hosted tenants, a hard external recipient limit of 2000 recipients in 24 hours would apply. In Microsoft's terminology, however, the term “recipient” refers to each individual email sent. The manufacturer calculates that 100 emails to five external recipients would count as 500 external recipients. In total, 10,000 recipients per day should still be possible, meaning that with maximum utilization, an additional 8000 emails could have been sent to internal users within a 24-hour period.

Initially, Microsoft recommended affected customers switch to Azure Communication Services for Email. This was specifically developed for high volumes of emails sent to external recipients.

(dmk)