mickael-kerjean/filestash · error

cannot send mail - reason=%s

Error message

cannot send mail - reason=%s

What it means

Wraps a failure from gomail's DialAndSend in sendInvitateMail. It fires when the SMTP dial or send fails — unreachable email server, wrong port/credentials, TLS rejection, or recipient refusal — after the mail subject/body have been templated for the user. Raised to UserManagementHandler, aborting the invitation/notification email.

Source

Thrown at server/plugin/plg_authenticate_local/notify.go:51

	cfg, err := getPluginData()
	if err != nil {
		return err
	} else if cfg.GetMailSubject() == "" || cfg.GetMailBody() == "" {
		return nil
	}
	m := gomail.NewMessage()
	m.SetHeader("From", Config.Get("email.from").String())
	m.SetHeader("To", user.Email)
	m.SetHeader("Subject", withTemplate(cfg.GetMailSubject(), user))
	m.SetBody("text/plain", withTemplate(cfg.GetMailBody(), user))
	d := gomail.NewDialer(
		Config.Get("email.server").String(),
		Config.Get("email.port").Int(),
		Config.Get("email.username").String(),
		Config.Get("email.password").String(),
	)
	if err := d.DialAndSend(m); err != nil {
		return fmt.Errorf("cannot send mail - reason=%s", err.Error())
	}
	Log.Info("plg_authenticate_simple::notification action=sent email=%s", user.Email)
	return nil
}

func withTemplate(in string, user User) string {
	var b bytes.Buffer
	tmpl, err := template.New("app").Parse(in)
	if err != nil {
		Log.Warning("plg_authenticate_simple::mail err=cannot_compile_template")
		return in
	}
	tmpl.Execute(&b, map[string]string{
		"instance_url": Config.Get("general.host").String(),
		"user":         user.Email,
		"password":     user.Password,
		"role":         user.Role,
	})

View on GitHub (pinned to 78f756eb94)

Solutions

1. Verify email.server, email.port, email.username, email.password and email.from in the config are correct
2. Test SMTP connectivity (telnet/openssl s_client) to the mail server from the server host
3. Check the mail provider for rate limits or blocked recipient addresses
4. Log the underlying gomail error detail (the %s reason) to distinguish dial vs send failures

When it happens

Trigger: Thrown at server/plugin/plg_authenticate_local/notify.go:51 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of mickael-kerjean/filestash@78f756eb94 (2026-09-06). Data as JSON: /api/errors/8b5734f5b1eb12e8. Report an issue: GitHub.