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The _autodiscover._tcp SRV record is a critical DNS configuration used primarily by Microsoft Exchange and other email services to automate client configuration. It follows the standard SRV record format:

_service._proto.name. TTL class SRV priority weight port target.

In your specific case:

0 10 443 autodiscover.hostname.net.

This indicates:

• Priority: 0 (lower values have higher priority)
• Weight: 10 (used for load balancing when priorities are equal)
• Port: 443 (HTTPS)
• Target: autodiscover.hostname.net.

When moving to a new server, you need to:

1. Verify if the new host provides Autodiscover services
2. Determine if you need to maintain the same hostname or update it
3. Check if SSL certificates cover the new endpoint

For a migration where autodiscover moves to newprovider.com:

_autodiscover._tcp  3600 IN  SRV 0 10 443 autodiscover.newprovider.com.

Use these PowerShell commands to verify:

Resolve-DnsName -Type SRV _autodiscover._tcp.yourdomain.com
Test-OutlookWebServices -Identity user@domain.com -Verbose

1. Certificate errors often occur when the SSL doesn't match the autodiscover hostname.
2. DNS propagation delays may cause temporary failures.
3. Firewall rules must allow traffic to port 443 on the new server.

The _autodiscover._tcp SRV record is a critical DNS configuration primarily used by Microsoft Exchange and other email services to enable automatic client configuration. When an email client (like Outlook) attempts to connect to an Exchange server, it queries this record to discover the correct connection endpoint without requiring manual setup.

The typical format appears as:

_autodiscover._tcp.example.com. 3600 IN SRV 0 10 443 autodiscover.example.net.

Breaking down the components:

• 0: Priority (lower values get higher precedence)
• 10: Weight for load balancing
• 443: TCP port (typically HTTPS)
• autodiscover.example.net.: Target host

When moving servers, you'll need to:

1. Update the target host in your SRV record
2. Ensure the new server has properly configured Autodiscover services
3. Maintain the old record temporarily during migration (with lower priority)

Here's how to implement this in BIND format:

; AutoDiscover SRV record
_autodiscover._tcp    3600    IN    SRV    0 10 443 autodiscover.newhost.net.

Test your configuration using these tools:

• Microsoft Remote Connectivity Analyzer
• nslookup -q=srv _autodiscover._tcp.yourdomain.com
• dig SRV _autodiscover._tcp.yourdomain.com

For connection problems:

# Test HTTP connectivity
curl -v https://autodiscover.yourdomain.com/autodiscover/autodiscover.xml

Check for these responses:

• 401 Unauthorized: Normal (service exists)
• 404 Not Found: Incorrect configuration

For redundancy, configure multiple SRV records with different priorities:

_autodiscover._tcp    3600    IN    SRV    0 10 443 primary.autodiscover.net.
_autodiscover._tcp    3600    IN    SRV    10 10 443 backup.autodiscover.net.