Setting up professional email with a domain in Odoo involves configuring the domain properly, setting up email servers in Odoo, and ensuring that the domain settings are compatible with Odoo's email system. Here's a detailed guide to help you resolve the issue:

1. Domain Registration and DNS Configuration

• Domain Registration: Ensure that your .net domain is correctly registered with a reliable domain registrar.
• DNS Configuration: Set up the necessary DNS records, including MX records, to point to your email hosting provider. You should have proper MX records that are pointing to your email server. Additionally, set up SPF, DKIM, and DMARC records to prevent email spoofing and ensure email deliverability.

2. Odoo Email Server Configuration

• Outgoing Email Server:
  • Go to Settings > Technical > Email > Outgoing Mail Servers.
  • Add a new outgoing mail server if not already configured. Fill in the following details:
    • SMTP Server: Your email provider’s SMTP server (e.g., smtp.yourdomain.com).
    • SMTP Port: Typically 465 for SSL or 587 for TLS.
    • Username: The full email address (e.g., name@companyname.net).
    • Password: The password for the email address.
    • Connection Security: Choose SSL/TLS depending on your provider's recommendation.
  • Save and click "Test Connection" to ensure that the server settings are correct.
• Incoming Mail Server:
  • Configure the incoming mail server (IMAP/POP) if you want to handle inbound emails within Odoo.
  • Navigate to Settings > Technical > Email > Incoming Mail Servers.
  • Configure similar settings as the outgoing server but for IMAP or POP3.

3. User Creation and Email Aliases

• Create Users:
  • Go to Settings > Users & Companies > Users.
  • Create a user or edit an existing user to assign the email address (e.g., name@companyname.net).
• Email Aliases:
  • You can create aliases for users if you want multiple email addresses to forward to a single user.

4. Testing Email Functionality

• Test Sending Emails:
  • After configuring the email servers, try sending a test email to verify that the configuration is correct.
  • If the test email fails, review the error message provided by Odoo to diagnose the problem.

5. Troubleshooting the .net Domain Issue

• Sender Rejected and User Not Found Error:
  • Check the Email Address: Ensure that the email address used (e.g., name@companyname.net) is correctly configured and exists on the email server.
  • Review MX Records: Verify that your .net domain's MX records are correctly pointing to your email server. Misconfigured MX records can lead to emails being rejected.
  • Sender Authentication: Ensure that the outgoing email settings in Odoo match the authentication settings required by your email server. Sometimes email providers reject emails if the sender's domain does not match the authenticated domain.
  • Compatibility with Odoo: Some domains or email providers might require specific configurations. Ensure that your .net domain's email provider supports the same SMTP settings being used by your Gmail account.

6. Advanced Troubleshooting

• Check Logs: Review the Odoo logs for any additional error messages that might give you more insight into why the .net domain is being rejected.
• Contact Your Email Provider: If all settings appear correct, contact your email provider to ensure there are no blocks or specific configurations needed for .net domains.
• Network Issues: Sometimes, network issues or firewalls can block communication with certain domains. Ensure there are no such blocks in place.

7. Consider Using an Email Hosting Service

• If you continue facing issues with the .net domain, consider using a dedicated email hosting service like G Suite, Office 365, or Zoho Mail, which might offer better integration and support.

By following these steps, you should be able to resolve the issue with sending emails using your .net domain in Odoo. If the problem persists, providing more detailed error logs or contacting your domain/email provider might be necessary to diagnose and fix the issue.