Microsoft is currently resolving a DNS configuration problem that prevents some Exchange Online users from receiving one-time passcodes (OTP) needed to access encrypted emails.

## The Problem

When users receive encrypted messages through Exchange Online, they typically get a separate email containing a single-use access code. This OTP allows recipients using Gmail, Yahoo, or other non-Microsoft email services to view encrypted content through the Office 365 Message Encryption portal.

However, a DNS record misconfiguration has disrupted this process, leaving some users unable to receive these essential access codes. The issue specifically impacts users whose email systems perform DNS verification checks on incoming messages.

## Microsoft’s Response

In a service alert posted to the admin center, Microsoft acknowledged the problem and outlined their remediation efforts:

“DNS records for the domain that provides OTP email messages to encrypted messages became misconfigured, which is causing impact,” the company stated.

Microsoft has corrected the DNS configurations and is contacting affected users to verify the fix is working properly. The company has classified this as a critical service issue, indicating significant user impact.

## Pattern of DNS-Related Incidents

This incident continues a troubling pattern of DNS-related outages affecting Microsoft services:

– **February 2024**: Entra ID DNS authentication failures due to DNS changes
– **August 2023**: Global Hotmail delivery problems caused by misconfigured DNS SPF records
– **April 2021**: Widespread service outage triggered by overloaded Azure DNS servers due to a code defect

## Current Status

While Microsoft has not disclosed the full scope of users affected, the company is actively monitoring the situation and working to ensure complete resolution of the DNS configuration issues causing the OTP delivery failures.