In Files

  • net/smtp.rb

Net::SMTPSession

Net::SMTP

What is This Library?

This library provides functionality to send internet mail via SMTP, the Simple Mail Transfer Protocol. For details of SMTP itself, see [RFC2821] (www.ietf.org/rfc/rfc2821.txt).

What is This Library NOT?

This library does NOT provide functions to compose internet mails. You must create them by yourself. If you want better mail support, try RubyMail or TMail. You can get both libraries from RAA. (www.ruby-lang.org/en/raa.html)

FYI: the official documentation on internet mail is: [RFC2822] (www.ietf.org/rfc/rfc2822.txt).

Examples

Sending Messages

You must open a connection to an SMTP server before sending messages. The first argument is the address of your SMTP server, and the second argument is the port number. Using Net::SMTP.start with a block is the simplest way to do this. This way, the SMTP connection is closed automatically after the block is executed.

require 'net/smtp'
Net::SMTP.start('your.smtp.server', 25) do |smtp|
  # Use the SMTP object smtp only in this block.
end

Replace ‘your.smtp.server’ with your SMTP server. Normally your system manager or internet provider supplies a server for you.

Then you can send messages.

msgstr = <<END_OF_MESSAGE
From: Your Name <your@mail.address>
To: Destination Address <someone@example.com>
Subject: test message
Date: Sat, 23 Jun 2001 16:26:43 +0900
Message-Id: <unique.message.id.string@example.com>

This is a test message.
END_OF_MESSAGE

require 'net/smtp'
Net::SMTP.start('your.smtp.server', 25) do |smtp|
  smtp.send_message msgstr,
                    'your@mail.address',
                    'his_addess@example.com'
end

Closing the Session

You MUST close the SMTP session after sending messages, by calling the finish method:

# using SMTP#finish
smtp = Net::SMTP.start('your.smtp.server', 25)
smtp.send_message msgstr, 'from@address', 'to@address'
smtp.finish

You can also use the block form of Net::SMTP.start/SMTP#start. This closes the SMTP session automatically:

# using block form of SMTP.start
Net::SMTP.start('your.smtp.server', 25) do |smtp|
  smtp.send_message msgstr, 'from@address', 'to@address'
end

I strongly recommend this scheme. This form is simpler and more robust.

HELO domain

In almost all situations, you must provide a third argument to Net::SMTP.start/SMTP#start. This is the domain name which you are on (the host to send mail from). It is called the “HELO domain”. The SMTP server will judge whether it should send or reject the SMTP session by inspecting the HELO domain.

Net::SMTP.start('your.smtp.server', 25,
                'mail.from.domain') { |smtp| ... }

SMTP Authentication

The Net::SMTP class supports three authentication schemes; PLAIN, LOGIN and CRAM MD5. (SMTP Authentication: [RFC2554]) To use SMTP authentication, pass extra arguments to Net::SMTP.start/SMTP#start.

# PLAIN
Net::SMTP.start('your.smtp.server', 25, 'mail.from.domain',
                'Your Account', 'Your Password', :plain)
# LOGIN
Net::SMTP.start('your.smtp.server', 25, 'mail.from.domain',
                'Your Account', 'Your Password', :login)

# CRAM MD5
Net::SMTP.start('your.smtp.server', 25, 'mail.from.domain',
                'Your Account', 'Your Password', :cram_md5)

Constants

Revision

Attributes

address[R]

The address of the SMTP server to connect to.

open_timeout[RW]

Seconds to wait while attempting to open a connection. If the connection cannot be opened within this time, a TimeoutError is raised.

port[R]

The port number of the SMTP server to connect to.

read_timeout[R]

Seconds to wait while reading one block (by one read(2) call). If the read(2) call does not complete within this time, a TimeoutError is raised.

Public Class Methods

default_port() click to toggle source

The default SMTP port, port 25.

 
               # File net/smtp.rb, line 169
def SMTP.default_port
  25
end
            
new( address, port = nil ) click to toggle source

Creates a new Net::SMTP object.

address is the hostname or ip address of your SMTP server. port is the port to connect to; it defaults to port 25.

This method does not open the TCP connection. You can use ::start instead of ::new if you want to do everything at once. Otherwise, follow ::new with #start.

 
               # File net/smtp.rb, line 184
def initialize( address, port = nil )
  @address = address
  @port = (port || SMTP.default_port)
  @esmtp = true
  @socket = nil
  @started = false
  @open_timeout = 30
  @read_timeout = 60
  @error_occured = false
  @debug_output = nil
end
            
start(address, port = nil, helo = 'localhost.localdomain', user = nil, secret = nil, authtype = nil) click to toggle source

Creates a new Net::SMTP object and connects to the server.

This method is equivalent to:

Net::SMTP.new(address, port).start(helo_domain, account, password, authtype)

Example

Net::SMTP.start('your.smtp.server') do |smtp|
  smtp.send_message msgstr, 'from@example.com', ['dest@example.com']
end

Block Usage

If called with a block, the newly-opened Net::SMTP object is yielded to the block, and automatically closed when the block finishes. If called without a block, the newly-opened Net::SMTP object is returned to the caller, and it is the caller’s responsibility to close it when finished.

Parameters

address is the hostname or ip address of your smtp server.

port is the port to connect to; it defaults to port 25.

helo is the HELO domain provided by the client to the server (see overview comments); it defaults to 'localhost.localdomain'.

The remaining arguments are used for SMTP authentication, if required or desired. user is the account name; secret is your password or other authentication token; and authtype is the authentication type, one of :plain, :login, or :cram_md5. See the discussion of SMTP Authentication in the overview notes.

Errors

This method may raise:

 
               # File net/smtp.rb, line 312
def SMTP.start(address, port = nil, helo = 'localhost.localdomain',
               user = nil, secret = nil, authtype = nil,
               &block)   # :yield: smtp
  new(address, port).start(helo, user, secret, authtype, &block)
end
            

Public Instance Methods

esmtp() click to toggle source
Alias for: esmtp?
esmtp=( bool ) click to toggle source

Set whether to use ESMTP or not. This should be done before calling start. Note that if start is called in ESMTP mode, and the connection fails due to a ProtocolError, the SMTP object will automatically switch to plain SMTP mode and retry (but not vice versa).

 
               # File net/smtp.rb, line 213
def esmtp=( bool )
  @esmtp = bool
end
            
esmtp?() click to toggle source

true if the SMTP object uses ESMTP (which it does by default).

 
               # File net/smtp.rb, line 202
def esmtp?
  @esmtp
end
            
Also aliased as: esmtp
finish() click to toggle source

Finishes the SMTP session and closes TCP connection. Raises IOError if not started.

 
               # File net/smtp.rb, line 419
def finish
  raise IOError, 'not yet started' unless started?
  do_finish
end
            
inspect() click to toggle source

Provide human-readable stringification of class state.

 
               # File net/smtp.rb, line 197
def inspect
  "#<#{self.class} #{@address}:#{@port} started=#{@started}>"
end
            
open_message_stream( from_addr, *to_addrs ) click to toggle source

Opens a message writer stream and gives it to the block. The stream is valid only in the block, and has these methods:

puts(str = ”)

outputs STR and CR LF.

print(str)

outputs STR.

printf(fmt, *args)

outputs sprintf(fmt,*args).

write(str)

outputs STR and returns the length of written bytes.

<<(str)

outputs STR and returns self.

If a single CR (“r”) or LF (“n”) is found in the message, it is converted to the CR LF pair. You cannot send a binary message with this method.

Parameters

from_addr is a String representing the source mail address.

to_addr is a String or Strings or Array of Strings, representing the destination mail address or addresses.

Example

Net::SMTP.start('smtp.example.com', 25) do |smtp|
  smtp.open_message_stream('from@example.com', ['dest@example.com']) do |f|
    f.puts 'From: from@example.com'
    f.puts 'To: dest@example.com'
    f.puts 'Subject: test message'
    f.puts
    f.puts 'This is a test message.'
  end
end

Errors

This method may raise:

 
               # File net/smtp.rb, line 523
def open_message_stream( from_addr, *to_addrs, &block ) # :yield: stream
  send0(from_addr, to_addrs.flatten) {
    @socket.write_message_by_block(&block)
  }
end
            
Also aliased as: ready
read_timeout=( sec ) click to toggle source

Set the number of seconds to wait until timing-out a read(2) call.

 
               # File net/smtp.rb, line 237
def read_timeout=( sec )
  @socket.read_timeout = sec if @socket
  @read_timeout = sec
end
            
ready( from_addr, *to_addrs ) click to toggle source
Alias for: open_message_stream
send_mail( msgstr, from_addr, *to_addrs ) click to toggle source
Alias for: send_message
send_message( msgstr, from_addr, *to_addrs ) click to toggle source

Sends msgstr as a message. Single CR (“r”) and LF (“n”) found in the msgstr, are converted into the CR LF pair. You cannot send a binary message with this method. msgstr should include both the message headers and body.

from_addr is a String representing the source mail address.

to_addr is a String or Strings or Array of Strings, representing the destination mail address or addresses.

Example

Net::SMTP.start('smtp.example.com') do |smtp|
  smtp.send_message msgstr,
                    'from@example.com',
                    ['dest@example.com', 'dest2@example.com']
end

Errors

This method may raise:

 
               # File net/smtp.rb, line 470
def send_message( msgstr, from_addr, *to_addrs )
  send0(from_addr, to_addrs.flatten) {
    @socket.write_message msgstr
  }
end
            
Also aliased as: send_mail, sendmail
sendmail( msgstr, from_addr, *to_addrs ) click to toggle source
Alias for: send_message
set_debug_output( arg ) click to toggle source

WARNING: This method causes serious security holes. Use this method for only debugging.

Set an output stream for debug logging. You must call this before start.

# example
smtp = Net::SMTP.new(addr, port)
smtp.set_debug_output $stderr
smtp.start do |smtp|
  ....
end
 
               # File net/smtp.rb, line 256
def set_debug_output( arg )
  @debug_output = arg
end
            
start(helo = 'localhost.localdomain', user = nil, secret = nil, authtype = nil) click to toggle source

Opens a TCP connection and starts the SMTP session.

Parameters

helo is the HELO domain that you'll dispatch mails from; see the discussion in the overview notes.

If both of user and secret are given, SMTP authentication will be attempted using the AUTH command. authtype specifies the type of authentication to attempt; it must be one of :login, :plain, and :cram_md5. See the notes on SMTP Authentication in the overview.

Block Usage

When this methods is called with a block, the newly-started SMTP object is yielded to the block, and automatically closed after the block call finishes. Otherwise, it is the caller’s responsibility to close the session when finished.

Example

This is very similar to the class method ::start.

require 'net/smtp' 
smtp = Net::SMTP.new('smtp.mail.server', 25)
smtp.start(helo_domain, account, password, authtype) do |smtp|
  smtp.send_message msgstr, 'from@example.com', ['dest@example.com']
end

The primary use of this method (as opposed to ::start) is probably to set debugging (#set_debug_output) or ESMTP (#esmtp=), which must be done before the session is started.

Errors

If session has already been started, an IOError will be raised.

This method may raise:

 
               # File net/smtp.rb, line 373
def start(helo = 'localhost.localdomain',
          user = nil, secret = nil, authtype = nil)   # :yield: smtp
  if block_given?
    begin
      do_start(helo, user, secret, authtype)
      return yield(self)
    ensure
      do_finish
    end
  else
    do_start(helo, user, secret, authtype)
    return self
  end
end
            
started?() click to toggle source

true if the SMTP session has been started.

 
               # File net/smtp.rb, line 319
def started?
  @started
end
            

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