Route53 - Transferring a domain in... Max retries exceeded with url: /api/call.cgi

The error you're encountering appears to be a technical issue during the domain transfer process to Route 53. This specific error message suggests there's a connection problem with the registrar's API that Route 53 is trying to communicate with.

When transferring domains to Route 53, there are several common issues that can occur:

1. Authorization issues: ICANN requires authorization from the registrant contact for domain transfers. Make sure you're checking your email for an authorization link that must be clicked within 5-15 days (depending on the top-level domain). If you miss this window, the transfer will fail.

2. Domain transfer restrictions: If you recently registered or transferred the domain (within the last 60 days), it cannot be transferred again. This is a standard industry practice.

3. Domain quota limits: AWS accounts have a default limit on the number of domains you can hold (typically 20 domains). If you've reached this limit, transfers will fail with a message about "Number of domains exceeded for the account."

4. Premium domain restrictions: Route 53 doesn't support transferring premium domains. If your domain is classified as a premium domain, you'll need to use a different registrar.

For your specific technical error, I recommend:

1. Try the transfer again after some time as it might be a temporary connection issue.
2. Ensure your transfer authorization code (EPP code) from your current registrar is valid.
3. Contact AWS Support for assistance. Even if you're on the Basic support plan, domain registration issues are covered free of charge under the Account and Billing category.
   Sources
   Route 53 Domain transfer to AWS fails: Number of domains exceeded for the account | AWS re:Post
   Transfer or register premium or unsupported domains with Route 53 | AWS re:Post
   Transferring my domain to Amazon Route 53 failed - Amazon Route 53
   Route 53: Can't transfer out a domain to another domain | AWS re:Post