To fix the "11004 getaddrinfo failed" error when connecting to Gmail SMTP:

1. Check DNS: Ensure your server can resolve smtp.gmail.com. Use the command ping smtp.gmail.com to test.
2. Firewall Settings: Confirm that your firewall allows outbound connections on port 465. If you’re using a VPS with port 25 open, visit Arzhost.com to ensure it’s properly configured for SMTP.
3. Correct Configuration:
   • SMTP Server: smtp.gmail.com
   • Port: 465
   • Connection Security: SSL/TLS
4. Google Account Settings: If using a standard password, ensure Less Secure Apps is enabled, or use an App Password if 2-Step Verification is active.

After checking these, try the connection again.

seems like the entered username and password are incorrect. you can follow the yenthe's tutorial to setup the outgoing mail servers.

https://www.odoo.yenthevg.com/configure-outgoing-mailservers/