Autodiscover Failed

Outlook can't automatically configure your Exchange Online account. We'll fix the DNS, certificate, and connectivity issues.

⚠️ Business Consequence: Why This Matters

  • Financial Impact: New hire onboarding delays = lost productivity ($300–$600 per day per user)
  • Compliance Exposure: Users unable to access email = missed regulatory deadlines
  • Operational Risk: Mass Autodiscover failures during domain migration halt operations
  • Help Desk Overload: 10–20+ tickets per failed domain during onboarding waves

Average diagnosis time: 5–15 minutes — prevents onboarding cascade failures.

Autodiscover Quick Facts

  • What it is: Outlook automatically finds your mailbox settings
  • Time to fix: 5-15 minutes (usually just DNS)
  • Workaround: You can add the account manually while we fix it
  • Root cause: Almost always a DNS CNAME record issue

What Users See

Outlook shows one of these errors:

  • "Autodiscover failed"
  • "Cannot find Exchange server"
  • "The username or password is incorrect" (after autodiscover fails)

Key clue: If you can manually add the account to Outlook (by entering outlook.office365.com), it's a DNS issue, not an authentication issue.

Most Common Root Causes

In order of likelihood:

  1. Missing DNS CNAME: autodiscover.yourdomain.com doesn't exist in DNS
  2. Wrong CNAME target: Points to your on-premises server instead of Exchange Online
  3. DNS propagation delay: CNAME was just added but hasn't spread globally yet (wait 30 min)
  4. SSL certificate problem: Certificate doesn't match the domain name
  5. Firewall blocking: Your firewall blocks access to autodiscover.yourdomain.com

Diagnostic Steps (5-15 minutes)

Step 1: Check Your Autodiscover DNS (2 min)

Open Command Prompt and run:

nslookup autodiscover.yourdomain.com

Good result: Shows autodiscover.outlook.com

Bad result: Shows your on-prem server or "Not Found" → Go to Step 2

Step 2: Check Global DNS Propagation (2 min)

Your local DNS may be cached. Check if the fix has spread worldwide:

Use MXToolbox CNAME Lookup

Enter autodiscover.yourdomain.com. If it shows the right target everywhere, DNS is correct. Wait 5-10 minutes and retry Outlook.

Step 3: Test Connection to Autodiscover (2 min)

Can your computer reach the autodiscover server? Run:

telnet autodiscover.yourdomain.com 443

Good: Connection succeeds (you see a blank screen or "Connected")

Bad: "Could not open connection" → Firewall is blocking it

Step 4: Test from Outlook (2 min)

Let Outlook test autodiscover itself:

  1. Open Outlook
  2. Go to File > Account Settings > Account Settings
  3. Find your account and click it
  4. Click Repair (or Test Account Settings if available)
  5. Check the log. Look for "Autodiscover:" entry

Fixes (By Root Cause)

Fix 1: Add the DNS CNAME Record (10 min)

When to use: Step 1 shows "Not Found" or wrong target

  1. Log into your DNS provider (GoDaddy, Microsoft 365, Cloudflare, etc.)
  2. Find the DNS records section
  3. Add a new CNAME record:
    • Name: autodiscover
    • Type: CNAME
    • Target: autodiscover.outlook.com
  4. Save and wait 15-30 minutes
  5. Run Step 1 again to verify the change
  6. Try Outlook again

Fix 2: Use Manual Configuration (2 min - Temporary Workaround)

When to use: While waiting for DNS or certificate fix

  1. In Outlook, add account manually
  2. Choose "Exchange" account type
  3. Uncheck "Use Autodiscover"
  4. Enter server: outlook.office365.com
  5. Set port to 443 and encryption to TLS
  6. This works until you fix autodiscover

Fix 3: Allow Firewall Access (5 min)

When to use: Step 3 shows "Could not open connection"

  • Contact your network/firewall team
  • Ask to allow outbound HTTPS (port 443) to autodiscover.yourdomain.com
  • Test again after the firewall change

When to Escalate to Support

  • All steps passed but Outlook still fails: There's a deeper issue
  • Certificate errors appear: The cert doesn't match the domain
  • Hybrid setup problems: Your on-premises server is involved

Frequently Asked Questions

What is Autodiscover and why does it fail?

Autodiscover lets Outlook automatically find mailbox settings. It fails most often due to a missing or wrong DNS CNAME for autodiscover.yourdomain.com.

Can I use manual server settings as a workaround?

Yes—add the account manually with server outlook.office365.com (TLS 443) while DNS is fixed.

How long do DNS changes take to propagate?

Usually 5–30 minutes. Global propagation can take longer; verify via an external DNS checker.

Does certificate mismatch break Autodiscover?

Yes. If the HTTPS certificate bound in IIS does not include autodiscover.yourdomain.com, Outlook will fail validation.

Related Guides

Connection Issues Hybrid Exchange Message Trace