1package smtpserver

2

3import (

4 "context"

5 "fmt"

6

7 "github.com/mjl-/mox/dsn"

8 "github.com/mjl-/mox/queue"

9 "github.com/mjl-/mox/smtp"

10 "github.com/mjl-/mox/store"

11)

12

13// compose dsn message and add it to the queue for delivery to rcptTo.

14func queueDSN(ctx context.Context, c *conn, rcptTo smtp.Path, m dsn.Message, requireTLS bool) error {

15 buf, err := m.Compose(c.log, false)

16 if err != nil {

17 return err

18 }

19 var bufUTF8 []byte

20 if c.smtputf8 {

21 bufUTF8, err = m.Compose(c.log, true)

22 if err != nil {

23 c.log.Errorx("composing dsn with utf-8 for incoming delivery for unknown user, continuing with ascii-only dsn", err)

24 }

25 }

26

27 f, err := store.CreateMessageTemp("smtp-dsn")

28 if err != nil {

29 return fmt.Errorf("creating temp file: %w", err)

30 }

31 defer store.CloseRemoveTempFile(c.log, f, "smtpserver dsn message")

32

33 if _, err := f.Write([]byte(buf)); err != nil {

34 return fmt.Errorf("writing dsn file: %w", err)

35 }

36

37 // Queue DSN with null reverse path so failures to deliver will eventually drop the

38 // message instead of causing delivery loops.

39 // ../rfc/3464:433

40 const has8bit = false

41 const smtputf8 = false

42 var reqTLS *bool

43 if requireTLS {

44 reqTLS = &requireTLS

45 }

46 qm := queue.MakeMsg("", smtp.Path{}, rcptTo, has8bit, smtputf8, int64(len(buf)), m.MessageID, nil, reqTLS)

47 qm.DSNUTF8 = bufUTF8

48 if err := queue.Add(ctx, c.log, &qm, f); err != nil {

49 return err

50 }

51 return nil

52}

53