Google announced they are now sending out Google Webmaster Tools alerts for crawl errors.
Google grouped the errors in two buckets.
(1) Site Error alerts for major site-wide problems
(2) URL Error anomaly alerts for potentially less critical issues
The Site-Wide Problems Alerts Can Include:
- Your DNS server is down or misconfigured.
- Your web server itself is firewalled off.
- Your web server is refusing connections from Googlebot.
- Your web server is overloaded, or down.
- Your site’s robots.txt is inaccessible.
The URL Error Anomaly Alerts Can Include:
- Server error
- Soft 404
- Access denied
- Not found
- Not followed
Since Googlebot regularly visits your site, we know when your site exhibits connectivity issues or suddenly spikes in pages returning HTTP error response codes (e.g. 404 File Not Found, 403 Forbidden, 503 Service Unavailable, etc). If your site is timing out or is exhibiting systemic errors when accessed by Googlebot, other visitors to your site might be having the same problem!
This is just one more reason to sign up with Google Webmaster Tools and enable email forwarding within alerts.