Thus, starting March 1, 2026, Exchange Online will begin phasing out Basic authentication for sending emails via SMTP AUTH. At first, fewer attempts will be blocked, but by April 30, 2026, this ...

Microsoft warned today that it will permanently turn off Exchange Online basic authentication starting early January 2023 to improve security.

A massive botnet of over 130,000 compromised devices is conducting password-spray attacks against Microsoft 365 (M365) accounts worldwide, targeting basic authentication to evade multi-factor ...