send.go

Documentation: github.com/go-mail/mail

     1  package mail
     2  
     3  import (
     4  	"errors"
     5  	"fmt"
     6  	"io"
     7  	stdmail "net/mail"
     8  )
     9  
    10  // Sender is the interface that wraps the Send method.
    11  //
    12  // Send sends an email to the given addresses.
    13  type Sender interface {
    14  	Send(from string, to []string, msg io.WriterTo) error
    15  }
    16  
    17  // SendCloser is the interface that groups the Send and Close methods.
    18  type SendCloser interface {
    19  	Sender
    20  	Close() error
    21  }
    22  
    23  // A SendFunc is a function that sends emails to the given addresses.
    24  //
    25  // The SendFunc type is an adapter to allow the use of ordinary functions as
    26  // email senders. If f is a function with the appropriate signature, SendFunc(f)
    27  // is a Sender object that calls f.
    28  type SendFunc func(from string, to []string, msg io.WriterTo) error
    29  
    30  // Send calls f(from, to, msg).
    31  func (f SendFunc) Send(from string, to []string, msg io.WriterTo) error {
    32  	return f(from, to, msg)
    33  }
    34  
    35  // Send sends emails using the given Sender.
    36  func Send(s Sender, msg ...*Message) error {
    37  	for i, m := range msg {
    38  		if err := send(s, m); err != nil {
    39  			return &SendError{Cause: err, Index: uint(i)}
    40  		}
    41  	}
    42  
    43  	return nil
    44  }
    45  
    46  func send(s Sender, m *Message) error {
    47  	from, err := m.getFrom()
    48  	if err != nil {
    49  		return err
    50  	}
    51  
    52  	to, err := m.getRecipients()
    53  	if err != nil {
    54  		return err
    55  	}
    56  
    57  	if err := s.Send(from, to, m); err != nil {
    58  		return err
    59  	}
    60  
    61  	return nil
    62  }
    63  
    64  func (m *Message) getFrom() (string, error) {
    65  	from := m.header["Sender"]
    66  	if len(from) == 0 {
    67  		from = m.header["From"]
    68  		if len(from) == 0 {
    69  			return "", errors.New(`gomail: invalid message, "From" field is absent`)
    70  		}
    71  	}
    72  
    73  	return parseAddress(from[0])
    74  }
    75  
    76  func (m *Message) getRecipients() ([]string, error) {
    77  	n := 0
    78  	for _, field := range []string{"To", "Cc", "Bcc"} {
    79  		if addresses, ok := m.header[field]; ok {
    80  			n += len(addresses)
    81  		}
    82  	}
    83  	list := make([]string, 0, n)
    84  
    85  	for _, field := range []string{"To", "Cc", "Bcc"} {
    86  		if addresses, ok := m.header[field]; ok {
    87  			for _, a := range addresses {
    88  				addr, err := parseAddress(a)
    89  				if err != nil {
    90  					return nil, err
    91  				}
    92  				list = addAddress(list, addr)
    93  			}
    94  		}
    95  	}
    96  
    97  	return list, nil
    98  }
    99  
   100  func addAddress(list []string, addr string) []string {
   101  	for _, a := range list {
   102  		if addr == a {
   103  			return list
   104  		}
   105  	}
   106  
   107  	return append(list, addr)
   108  }
   109  
   110  func parseAddress(field string) (string, error) {
   111  	addr, err := stdmail.ParseAddress(field)
   112  	if err != nil {
   113  		return "", fmt.Errorf("gomail: invalid address %q: %v", field, err)
   114  	}
   115  	return addr.Address, nil
   116  }
   117
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