Resolving server errors often involves several steps:
- Check Server Logs: Examine server logs to identify the specific error messages and codes. - Verify Configuration: Ensure that your server configuration, including DNS settings and SMTP authentication, is correct. - Contact ISPs: If your IP is blocked, contact the Internet Service Providers (ISPs) to request removal from their blocklist. - Retry Sending: For temporary errors (4xx), retry sending the emails after some time.