New SMTP library and refactoring of mailer code

domain/smtp/send.go

@@ -0,0 +1,114 @@
+// Copyright 2016 Documize Inc. <legal@documize.com>. All rights reserved.
+//
+// This software (Documize Community Edition) is licensed under
+// GNU AGPL v3 http://www.gnu.org/licenses/agpl-3.0.en.html
+//
+// You can operate outside the AGPL restrictions by purchasing
+// Documize Enterprise Edition and obtaining a commercial license
+// by contacting <sales@documize.com>.
+//
+// https://documize.com
+
+// Package smtp provides access to SMTP server for sending email.
+package smtp
+
+import (
+	"crypto/tls"
+	"encoding/base64"
+	"strings"
+
+	"github.com/documize/community/core/mail"
+)
+
+// Config is used to create SMTP server connection
+type Config struct {
+	// IP/hostname of SMTP server
+	Host string
+
+	// Port number of SMTP server
+	Port int
+
+	// Username for authentication with SMTP server
+	Username string
+
+	// Password for authentication with SMTP server
+	Password string
+
+	// SenderEmail is FROM address
+	SenderEmail string
+
+	// SenderName is FROM display name
+	SenderName string
+
+	// AnonymousAuth does not send username/password to server
+	AnonymousAuth bool
+
+	// Base64EncodeCredentials encodes User and Password as base64 before sending to SMTP server
+	Base64EncodeCredentials bool
+
+	// UseSSL uses SMTP SSL connection with SMTP server
+	UseSSL bool
+
+	// SkipSSLVerify allows unverified certificates
+	SkipSSLVerify bool
+}
+
+// Connect returns open connection to server for sending email
+func Connect(c Config) (d *mail.Dialer, err error) {
+	// prepare credentials
+	u := strings.TrimSpace(c.Username)
+	p := strings.TrimSpace(c.Password)
+
+	// anonymous, no credentials
+	if c.AnonymousAuth {
+		u = ""
+		p = ""
+	}
+
+	// base64 encode if required
+	if c.Base64EncodeCredentials {
+		u = base64.StdEncoding.EncodeToString([]byte(u))
+		p = base64.StdEncoding.EncodeToString([]byte(p))
+	}
+
+	// basic server
+	d = mail.NewDialer(c.Host, c.Port, u, p)
+
+	// use SSL
+	d.SSL = c.UseSSL
+
+	// verify SSL cert chain
+	d.TLSConfig = &tls.Config{InsecureSkipVerify: c.SkipSSLVerify}
+
+	// TLS mode
+	d.StartTLSPolicy = mail.OpportunisticStartTLS
+
+	return d, nil
+}
+
+// EmailMessage represents email to be sent.
+type EmailMessage struct {
+	ToEmail  string
+	ToName   string
+	Subject  string
+	BodyHTML string
+}
+
+// SendMessage sends email using specified SMTP connection
+func SendMessage(d *mail.Dialer, c Config, em EmailMessage) (b bool, err error) {
+	m := mail.NewMessage()
+
+	// participants
+	m.SetHeader("From", m.FormatAddress(c.SenderEmail, c.SenderName))
+	m.SetHeader("To", m.FormatAddress(em.ToEmail, em.ToName))
+
+	// content
+	m.SetHeader("Subject", em.Subject)
+	m.SetBody("text/html", em.BodyHTML)
+
+	// send email
+	if err = d.DialAndSend(m); err != nil {
+		return false, err
+	}
+	return true, nil
+}