gomail/send.go

117 lines
2.4 KiB
Go

package gomail
import (
"errors"
"fmt"
"io"
"net/mail"
)
// Sender is the interface that wraps the Send method.
//
// Send sends an email to the given addresses.
type Sender interface {
Send(from string, to []string, msg io.WriterTo) error
}
// SendCloser is the interface that groups the Send and Close methods.
type SendCloser interface {
Sender
Close() error
}
// A SendFunc is a function that sends emails to the given adresses.
//
// The SendFunc type is an adapter to allow the use of ordinary functions as
// email senders. If f is a function with the appropriate signature, SendFunc(f)
// is a Sender object that calls f.
type SendFunc func(from string, to []string, msg io.WriterTo) error
// Send calls f(from, to, msg).
func (f SendFunc) Send(from string, to []string, msg io.WriterTo) error {
return f(from, to, msg)
}
// Send sends emails using the given Sender.
func Send(s Sender, msg ...*Message) error {
for i, m := range msg {
if err := send(s, m); err != nil {
return fmt.Errorf("gomail: could not send email %d: %v", i+1, err)
}
}
return nil
}
func send(s Sender, m *Message) error {
from, err := m.getFrom()
if err != nil {
return err
}
to, err := m.getRecipients()
if err != nil {
return err
}
if err := s.Send(from, to, m); err != nil {
return err
}
return nil
}
func (m *Message) getFrom() (string, error) {
from := m.header["Sender"]
if len(from) == 0 {
from = m.header["From"]
if len(from) == 0 {
return "", errors.New(`gomail: invalid message, "From" field is absent`)
}
}
return parseAddress(from[0])
}
func (m *Message) getRecipients() ([]string, error) {
n := 0
for _, field := range []string{"To", "Cc", "Bcc"} {
if addresses, ok := m.header[field]; ok {
n += len(addresses)
}
}
list := make([]string, 0, n)
for _, field := range []string{"To", "Cc", "Bcc"} {
if addresses, ok := m.header[field]; ok {
for _, a := range addresses {
addr, err := parseAddress(a)
if err != nil {
return nil, err
}
list = addAddress(list, addr)
}
}
}
return list, nil
}
func addAddress(list []string, addr string) []string {
for _, a := range list {
if addr == a {
return list
}
}
return append(list, addr)
}
func parseAddress(field string) (string, error) {
addr, err := mail.ParseAddress(field)
if err != nil {
return "", fmt.Errorf("gomail: invalid address %q: %v", field, err)
}
return addr.Address, nil
}