forked from jpoehls/gophermail
/
smtp.go
105 lines (91 loc) · 1.81 KB
/
smtp.go
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package gophermail
import (
"net/mail"
"net/smtp"
)
// SendMail connects to the server at addr, switches to TLS if possible,
// authenticates with mechanism a if possible, and then sends the given Message.
//
// Based heavily on smtp.SendMail().
func SendMail(addr string, a smtp.Auth, msg *Message) error {
msgBytes, err := msg.Bytes()
if err != nil {
return err
}
c, err := smtp.Dial(addr)
if err != nil {
return err
}
if ok, _ := c.Extension("STARTTLS"); ok {
if err = c.StartTLS(nil); err != nil {
return err
}
}
if a != nil {
if ok, _ := c.Extension("AUTH"); ok {
if err = c.Auth(a); err != nil {
return err
}
}
}
// Sender
parsedAddr, err := parseAddress(msg.From)
if err != nil {
return err
}
if err = c.Mail(parsedAddr); err != nil {
return err
}
// To
err = rcpt(c, msg.To)
if err != nil {
return err
}
// CC
err = rcpt(c, msg.Cc)
if err != nil {
return err
}
// BCC
err = rcpt(c, msg.Bcc)
if err != nil {
return err
}
w, err := c.Data()
if err != nil {
return err
}
_, err = w.Write(msgBytes)
if err != nil {
return err
}
err = w.Close()
if err != nil {
return err
}
return c.Quit()
}
// rcpt parses the specified list of RFC 5322 addresses
// and calls smtp.Client.Rcpt() with each one.
func rcpt(c *smtp.Client, addresses []string) error {
for _, rcptAddr := range addresses {
parsedAddr, err := parseAddress(rcptAddr)
if err != nil {
return err
}
if err = c.Rcpt(parsedAddr); err != nil {
return err
}
}
return nil
}
// parseAddress parses a single RFC 5322 address and returns the
// e-mail address portion.
// e.g. "Barry Gibbs <bg@example.com>" would return "bg@example.com".
func parseAddress(address string) (string, error) {
a, err := mail.ParseAddress(address)
if err != nil {
return "", err
}
return a.Address, err
}