Billionmail/BillionMail · error

failed to read postfix config: %v

Error message

failed to read postfix config: %v

What it means

updatePostfixConfig reads Postfix main.cf (consts.POSTFIX_MAIN_CONF) with os.ReadFile before rewriting the smtpd_tls_cert_file/key_file lines. This error wraps the read failure and is raised by SetSSL and SetPostfixSSL when main.cf is missing or unreadable.

Source

Thrown at core/internal/service/mail_service/certificate.go:232

		return fmt.Errorf("private key data is empty")
	}

	// Validate certificate
	cInfo := acme.GetCertInfo(csrPem)

	if cInfo.Endtime == 0 {
		return fmt.Errorf("certificate is invalid")
	}

	return nil
}

// updatePostfixConfig updates Postfix configuration with new certificate
func (c *Certificate) updatePostfixConfig(csrPem, keyPem string) error {
	mainCf := public.AbsPath(consts.POSTFIX_MAIN_CONF)
	content, err := os.ReadFile(mainCf)
	if err != nil {
		return fmt.Errorf("failed to read postfix config: %v", err)
	}

	// Write certificate and key to files
	certPath := public.AbsPath(filepath.Join(consts.SSL_PATH, "postfix.crt"))
	keyPath := public.AbsPath(filepath.Join(consts.SSL_PATH, "postfix.key"))

	if err := os.WriteFile(certPath, []byte(csrPem), 0755); err != nil {
		return fmt.Errorf("failed to write certificate file: %v", err)
	}

	if err := os.WriteFile(keyPath, []byte(keyPem), 0755); err != nil {
		return fmt.Errorf("failed to write key file: %v", err)
	}

	// Update SSL certificate configuration
	config := string(content)
	config = c.updateConfigLine(config, "smtpd_tls_key_file", keyPath)
	config = c.updateConfigLine(config, "smtpd_tls_cert_file", certPath)

View on GitHub (pinned to fc36c76c05)

Solutions

1. Verify the main.cf path (postconf -h config_directory) and correct consts.POSTFIX_MAIN_CONF or the deployment mount
2. Install postfix / initialize the mail server before applying certificates
3. Grant the process read access to main.cf
4. Log the wrapped error to identify whether it is ENOENT or EACCES

mainCf := public.AbsPath(consts.POSTFIX_MAIN_CONF)
if _, err := os.Stat(mainCf); err != nil {
    return fmt.Errorf("postfix main.cf missing at %s — install/initialize postfix first: %w", mainCf, err)
}

if err := certService.SetSSL(csrPem, keyPem); err != nil {
    if strings.Contains(err.Error(), "failed to read postfix config") {
        log.Errorf("main.cf unreadable: %s", err)
        return ErrPostfixNotInstalled
    }
    return err
}

When it happens

Trigger: Calling SetSSL or SetPostfixSSL on a machine where AbsPath(consts.POSTFIX_MAIN_CONF) does not exist or cannot be read by the process user.

Common situations: Postfix not installed (fresh container/mail-server not initialized); custom postfix chroot/config directory; permission mismatch between the app user and /etc/postfix/main.cf.

Understand the failure class

Background: "Config file not found": what it means and how to fix it in docker-sync, Maven, Vagrant, Turborepo and other tools — this error's family across 60 libraries.

Related errors

• failed to read postfix master config: %v
• failed to update postfix master config: %v
• failed to write postfix master config: %v
• failed to write postfix config: %v
• failed to update SNI map: %v

AI-assisted analysis of Billionmail/BillionMail@fc36c76c05 (2026-09-05). Data as JSON: /api/errors/32f8b9832afb1679. Report an issue: GitHub.