mailpit/server/smtpd/smtp.go

package smtpd

import (
	"crypto/tls"
	"fmt"
	"net/smtp"

	"github.com/axllent/mailpit/config"
)

// Send will connect to a pre-configured SMTP server and send a message to one or more recipients.
func Send(from string, to []string, msg []byte) error {
	addr := fmt.Sprintf("%s:%d", config.SMTPRelayConfig.Host, config.SMTPRelayConfig.Port)

	c, err := smtp.Dial(addr)
	if err != nil {
		return err
	}

	defer c.Close()

	if config.SMTPRelayConfig.STARTTLS {
		conf := &tls.Config{ServerName: config.SMTPRelayConfig.Host}

		conf.InsecureSkipVerify = config.SMTPRelayConfig.AllowInsecure

		if err = c.StartTLS(conf); err != nil {
			return err
		}
	}

	var a smtp.Auth

	if config.SMTPRelayConfig.Auth == "plain" {
		a = smtp.PlainAuth("", config.SMTPRelayConfig.Username, config.SMTPRelayConfig.Password, config.SMTPRelayConfig.Host)
	}

	if config.SMTPRelayConfig.Auth == "cram-md5" {
		a = smtp.CRAMMD5Auth(config.SMTPRelayConfig.Username, config.SMTPRelayConfig.Secret)
	}

	if a != nil {
		if err = c.Auth(a); err != nil {
			return err
		}
	}
	if err = c.Mail(from); err != nil {
		return err
	}

	for _, addr := range to {
		if err = c.Rcpt(addr); err != nil {
			return err
		}
	}

	w, err := c.Data()
	if err != nil {
		return err
	}

	if _, err := w.Write(msg); err != nil {
		return err
	}

	if err := w.Close(); err != nil {
		return err
	}

	return c.Quit()
}