What Is Microsoft's Basic Auth Deprecation for Exchange Online SMTP?
Microsoft is retiring Basic Auth for SMTP AUTH in Exchange Online. This pushes adoption of OAuth 2.0 for supported email workflows. Basic Auth uses reusable username and password credentials. Review monitoring tools that rely on SMTP for alert notifications and checks.
Basic Auth deprecation targets legacy authentication. SMTP AUTH enables client submission of emails to Exchange Online servers. OAuth 2.0 uses access tokens instead of sending the account password with each request.
When Does Basic Auth for SMTP AUTH End in Exchange Online?
Basic Auth for SMTP AUTH remains unchanged through December 2026, then Microsoft plans to disable it by default for existing tenants. The final removal date is to be announced in the second half of 2027. Review current tenant settings before migration.
Phased Timeline Details
Use Exchange admin center reports to review authentication usage. Microsoft extended the timeline to give customers more time to modernize legacy workflows. Test supported authentication before the default changes.
Microsoft is retiring Basic Auth in phases. Plan migration around the applicable tenant settings and vendor timeline.
Review the Authentication Protocol information in Exchange admin center to identify clients still using Basic Auth.
How Does Basic Auth Deprecation Affect Website Uptime Monitoring?
Basic Auth deprecation can interrupt SMTP-dependent checks and alert delivery. Review the authentication options supported by each client and investigate failed authentication separately from website availability.
See Visual Sentinel Uptime Monitoring for website checks, separate from SMTP client configuration. Audit Exchange reports to identify affected email integrations.
Legacy SMTP authentication can fail when the method is disabled. Review alert noise and delivery failures after changing configuration.
What Risks Do Monitoring Tools Face from Basic Auth in 2026?
Tools using Basic Auth depend on reusable username and password credentials. Review how credentials are stored and transmitted. Authentication failures after a method is disabled can interrupt dependent clients.
Security Vulnerabilities
Unencrypted transmission can expose credentials. Use the supported secure authentication and transport settings for the client.
SSL Monitoring checks website certificate validity and expiry. Review OAuth support with the email client or provider.
How Can Monitoring Services Transition to OAuth 2.0 for SMTP Checks?
Monitoring services can use OAuth 2.0 for SMTP where the client supports it. Register the required app and test token acquisition and mail submission before changing the live client.
Configuration Steps
Obtain the required client credentials via Microsoft Entra ID for the supported OAuth flow. Test SMTP submission separately from website Performance Monitoring.
Azure AD registration creates app identities. Review token lifetimes and renewal behavior for the flow in use. SMTP clients like Postfix support OAuth via plugins.
Exchange Online accepts OAuth for submission on port 587. Test the client configuration and alert delivery after updating it.
What Preparation Steps Should SREs Take for Basic Auth Deprecation?
SREs audit SMTP AUTH usage in Exchange admin center reports, identifying Basic Auth dependencies. Update supported clients, test integrations and review authentication failures after the change.
Plan the supported OAuth migration for SMTP clients.
SREs schedule quarterly reviews. Test the endpoints and alert channels that depend on the changed configuration.
How Does Visual Sentinel Adapt to OAuth for Exchange Online Monitoring?
Visual Sentinel provides website checks and alerts. Review its results alongside separate Exchange Online authentication reports. Do not assume that website monitoring configures OAuth for SMTP clients.
Integration Guide
Visual Sentinel covers uptime, performance, SSL, DNS, visual and content checks. Website Checker provides an on-demand website availability check. Use the email provider's tools to test SMTP authentication.
Test the email client and the notification delivery path separately after authentication changes.
How Do Popular Monitoring Tools Compare in OAuth Support Post-2026?
Tools like Pingdom, UptimeRobot, and Datadog require verification for OAuth 2.0 SMTP AUTH compatibility. Compare general monitoring capabilities with Visual Sentinel vs Pingdom and Visual Sentinel vs UptimeRobot.
Authentication requirements depend on the client and service. See pricing for plan details, and test delivery after you change an integration.
| Tool | Basic Auth Support Post-2026 | OAuth 2.0 SMTP AUTH Check | Check Intervals Supported |
|---|---|---|---|
| Pingdom (SolarWinds) | Unverified | Unverified | 1 minute to 24 hours |
| UptimeRobot | Unverified | Unverified | 5 minutes to 1 hour |
| Datadog | Unverified | Unverified | 15 seconds to 1 day |
| Better Stack | Unverified | Unverified | 1 minute to 12 hours |
| Grafana Cloud | Unverified | Unverified | 30 seconds to 1 week |
| Site24x7 | Unverified | Unverified | 1 minute to 60 minutes |
Allow time to test legacy email workflows against the supported authentication method.
SREs verify tool compatibility via vendor docs. Pingdom (SolarWinds) scans from 100+ locations, from $16.50/month billed annually ($18 monthly) for 10 uptime checks. UptimeRobot free tier limits to 50 monitors with 5-minute intervals. Datadog Infrastructure Pro starts at $15/host/month on annual billing (Enterprise is $23), and Synthetic checks are billed per run.
Audit the monitoring clients and notifications that depend on SMTP authentication.
Test OAuth migrations with the email client and provider. Use Speed Test separately for website performance. Schedule audits every 90 days. Read More articles on secure transitions.
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What Is Microsoft's Basic Auth Deprecation for Exchange Online SMTP?
Microsoft is retiring Basic Auth for SMTP AUTH in Exchange Online. Review SMTP clients and alert integrations that use stored usernames and passwords, and test their supported authentication options.
When Does Basic Auth for SMTP AUTH End in Exchange Online?
Microsoft plans to disable Basic Auth for SMTP AUTH by default for existing tenants at the end of December 2026. A final removal date is to be announced in the second half of 2027. Review tenant settings and current vendor guidance before making changes.
How Does Basic Auth Deprecation Affect Website Uptime Monitoring?
An SMTP authentication change can interrupt email delivery or SMTP-dependent checks. Review the integrations you use and test their supported authentication methods. A failed authentication check needs investigation.
What Risks Do Monitoring Tools Face from Basic Auth in 2026?
Basic Auth uses reusable credentials. Services that rely on a method being retired can stop authenticating. Review credential handling and test supported authentication before changing the configuration.
How Can Monitoring Services Transition to OAuth 2.0 for SMTP Checks?
Register the required app and configure a supported OAuth 2.0 flow where the SMTP client supports it. Test token acquisition, mail submission and alert delivery before relying on the new configuration.
What Preparation Steps Should SREs Take for Basic Auth Deprecation?
Audit SMTP AUTH usage and identify dependent clients and notifications. Update supported integrations, test delivery and review authentication failures after the change.
