由于go默认tls.Config{ServerName: host, InsecureSkipVerify: false}，
func TestHtmlEmail(t *testing.T) {
opt := &EmailOptions{
User: "",
Password: "",
To: []string{""},
From: "",
Addr: "smtp.xxx.com:25",
}
auth := NewLoginAuth(opt.User, opt.Password)
pic, err := ioutil.ReadFile(`C:\Pictures\example.png`)
if err != nil {
t.Log(err)
}
dest := make([]byte, base64.StdEncoding.EncodedLen(len(pic)))
base64.StdEncoding.Encode(dest, pic)
buf := bytes.Buffer{}
fmt.Fprint(&buf, "<html><head></head><body><p>Test png</p><p><img src=\"data:image/png;base64,")
_, err = buf.Write(dest)
fmt.Fprint(&buf, "\"></p><body></html>")
err = sendMail(opt.Addr, auth, opt.From, opt.To, buf.Bytes(), "subject")
if err != nil {
t.Log(err)
}
}
type LoginAuth struct {
username, password string
}
func NewLoginAuth(username, password string) smtp.Auth {
return &LoginAuth{username, password}
}
func (a *LoginAuth) Start(server *smtp.ServerInfo) (string, []byte, error) {
return "LOGIN", []byte{}, nil
}
func (a *LoginAuth) Next(fromServer []byte, more bool) ([]byte, error) {
if more {
switch string(fromServer) {
case "Username:":
return []byte(a.username), nil
case "Password:":
return []byte(a.password), nil
default:
return nil, errors.New("Unknown fromServer")
}
}
return nil, nil
}
func sendMail(addr string, auth smtp.Auth, from string, to []string, msg []byte, subject string) error {
conn, err := smtp.Dial(addr)
host, _, _ := net.SplitHostPort(addr)
if err != nil {
return err
}
defer conn.Close()
if ok, _ := conn.Extension("STARTTLS"); ok {
config := &tls.Config{ServerName: host, InsecureSkipVerify: true}
if err = conn.StartTLS(config); err != nil {
return err
}
}
if auth != nil {
if ok, _ := conn.Extension("AUTH"); ok {
if err = conn.Auth(auth); err != nil {
return err
}
}
}
if err = conn.Mail(from); err != nil {
return err
}
for _, addr := range to {
if err = conn.Rcpt(addr); err != nil {
return err
}
}
w, err := conn.Data()
if err != nil {
return err
}
header := make(map[string]string)
header["Subject"] = subject
header["MIME-Version"] = "1.0"
header["To"] = strings.Join(to, ",")
header["From"] = from
header["Content-Type"] = "text/HTML; charset=\"utf-8\""
header["Content-Transfer-Encoding"] = "base64"
message := ""
for k, v := range header {
message += fmt.Sprintf("%s: %s\r\n", k, v)
}
message += "\r\n" + base64.StdEncoding.EncodeToString(msg)
_, err = w.Write([]byte(message))
if err != nil {
return err
}
err = w.Close()
if err != nil {
return err
}
return conn.Quit()
}
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