class EventMachine::Protocols::SmtpClient

Simple SMTP client

@example

email = EM::Protocols::SmtpClient.send(
  :domain=>"example.com",
  :host=>'localhost',
  :port=>25, # optional, defaults 25
  :starttls=>true, # use ssl
  :from=>"sender@example.com",
  :to=> ["to_1@example.com", "to_2@example.com"],
  :header=> {"Subject" => "This is a subject line"},
  :body=> "This is the body of the email"
)
email.callback{
  puts 'Email sent!'
}
email.errback{ |e|
  puts 'Email failed!'
}

Sending generated emails (using mailfactory)

mail = MailFactory.new
mail.to = 'someone@site.co'
mail.from = 'me@site.com'
mail.subject = 'hi!'
mail.text = 'hello world'
mail.html = '<h1>hello world</h1>'

email = EM::P::SmtpClient.send(
  :domain=>'site.com',
  :from=>mail.from,
  :to=>mail.to,
  :content=>"#{mail.to_s}\r\n.\r\n"
)

Attributes

args[W]

Public Class Methods

new() click to toggle source
# File lib/em/protocols/smtpclient.rb, line 71
def initialize
  @succeeded = nil
  @responder = nil
  @code = nil
  @msg = nil
end
send(args={}) click to toggle source

:host => required String

a string containing the IP address or host name of the SMTP server to connect to.

:port => optional

defaults to 25.

:domain => required String

This is passed as the argument to the EHLO command.

:starttls => optional Boolean

If it evaluates true, then the client will initiate STARTTLS with
the server, and abort the connection if the negotiation doesn't succeed.
TODO, need to be able to pass certificate parameters with this option.

:auth => optional Hash of auth parameters

If not given, then no auth will be attempted.
(In that case, the connection will be aborted if the server requires auth.)
Specify the hash value :type to determine the auth type, along with additional parameters
depending on the type.
Currently only :type => :plain is supported. Pass additional parameters :username (String),
and :password (either a String or a Proc that will be called at auth-time).

@example
  :auth => {:type=>:plain, :username=>"mickey@disney.com", :password=>"mouse"}

:from => required String

Specifies the sender of the message. Will be passed as the argument
to the MAIL FROM. Do NOT enclose the argument in angle-bracket (<>) characters.
The connection will abort if the server rejects the value.

:to => required String or Array of Strings

The recipient(s) of the message. Do NOT enclose
any of the values in angle-brackets (<>) characters. It's NOT a fatal error if one or more
recipients are rejected by the server. (Of course, if ALL of them are, the server will most
likely trigger an error when we try to send data.) An array of codes containing the status
of each requested recipient is available after the call completes. TODO, we should define
an overridable stub that will be called on rejection of a recipient or a sender, giving
user code the chance to try again or abort the connection.

:header => Required hash of values to be transmitted in the header of the message.

The hash keys are the names of the headers (do NOT append a trailing colon), and the values are strings
containing the header values. TODO, support Arrays of header values, which would cause us to
send that specific header line more than once.

@example
  :header => {"Subject" => "Bogus", "CC" => "myboss@example.com"}

:body => Optional string, defaults blank.

This will be passed as the body of the email message.
TODO, this needs to be significantly beefed up. As currently written, this requires the caller
to properly format the input into CRLF-delimited lines of 7-bit characters in the standard
SMTP transmission format. We need to be able to automatically convert binary data, and add
correct line-breaks to text data. I think the :body parameter should remain as it is, and we
should add a :content parameter that contains autoconversions and/or conversion parameters.
Then we can check if either :body or :content is present and do the right thing.

:content => Optional array or string

Alternative to providing header and body, an array or string of raw data which MUST be in
correct SMTP body format, including a trailing dot line

:verbose => Optional.

If true, will cause a lot of information (including the server-side of the
conversation) to be dumped to $>.
# File lib/em/protocols/smtpclient.rb, line 134
      def self.send args={}
        args[:port] ||= 25
        args[:body] ||= ""

      (I don't think it's possible for EM#connect to throw an exception under normal
      circumstances, so this original code is stubbed out. A connect-failure will result
      in the #unbind method being called without calling #connection_completed.)
      begin
        EventMachine.connect( args[:host], args[:port], self) {|c|
          # According to the EM docs, we will get here AFTER post_init is called.
          c.args = args
          c.set_comm_inactivity_timeout 60
        }
      rescue
        # We'll get here on a connect error. This code mimics the effect
        # of a call to invoke_internal_error. Would be great to DRY this up.
        # (Actually, it may be that we never get here, if EM#connect catches
        # its errors internally.)
        d = EM::DefaultDeferrable.new
        d.set_deferred_status(:failed, {:error=>[:connect, 500, "unable to connect to server"]})
        d
      end
        EventMachine.connect( args[:host], args[:port], self) {|c|
          # According to the EM docs, we will get here AFTER post_init is called.
          c.args = args
          c.set_comm_inactivity_timeout 60
        }
      end

Public Instance Methods

connection_completed() click to toggle source

@private

# File lib/em/protocols/smtpclient.rb, line 174
def connection_completed
  @responder = :receive_signon
  @msg = []
end
post_init() click to toggle source

@private

# File lib/em/protocols/smtpclient.rb, line 168
def post_init
  @return_values = OpenStruct.new
  @return_values.start_time = Time.now
end
receive_line(ln) click to toggle source

@private

# File lib/em/protocols/smtpclient.rb, line 196
def receive_line ln
  $>.puts ln if @args[:verbose]
  @range = ln[0...1].to_i
  @code = ln[0...3].to_i
  @msg << ln[4..-1]
  unless ln[3...4] == '-'
    $>.puts @responder if @args[:verbose]
    send @responder
    @msg.clear
  end
end
unbind() click to toggle source

We can get here in a variety of ways, all of them being failures unless the @succeeded flag is set. If a protocol success was recorded, then don't set a deferred success because the caller will already have done it (no need to wait until the connection closes to invoke the callbacks).

@private

# File lib/em/protocols/smtpclient.rb, line 185
def unbind
  unless @succeeded
    @return_values.elapsed_time = Time.now - @return_values.start_time
    @return_values.responder = @responder
    @return_values.code = @code
    @return_values.message = @msg
    set_deferred_status(:failed, @return_values)
  end
end

Private Instance Methods

invoke_auth() click to toggle source

Perform an authentication. If the caller didn't request one, then fall through to the mail-from state.

# File lib/em/protocols/smtpclient.rb, line 266
def invoke_auth
  if @args[:auth]
    if @args[:auth][:type] == :plain
      psw = @args[:auth][:password]
      if psw.respond_to?(:call)
        psw = psw.call
      end
      #str = Base64::encode64("\0#{@args[:auth][:username]}\0#{psw}").chomp
      str = ["\00##{@args[:auth][:username]}\00##{psw}"].pack("m").gsub(/\n/, '')
      send_data "AUTH PLAIN #{str}\r\n"
      @responder = :receive_auth_response
    else
      return invoke_internal_error("unsupported auth type")
    end
  else
    invoke_mail_from
  end
end
invoke_data() click to toggle source
# File lib/em/protocols/smtpclient.rb, line 319
def invoke_data
  send_data "DATA\r\n"
  @responder = :receive_data_response
end
invoke_error() click to toggle source

We encountered an error from the server and will close the connection. Use the error and message the server returned.

# File lib/em/protocols/smtpclient.rb, line 213
def invoke_error
  @return_values.elapsed_time = Time.now - @return_values.start_time
  @return_values.responder = @responder
  @return_values.code = @code
  @return_values.message = @msg
  set_deferred_status :failed, @return_values
  send_data "QUIT\r\n"
  close_connection_after_writing
end
invoke_internal_error(msg = "???") click to toggle source

We encountered an error on our side of the protocol and will close the connection. Use an extra-protocol error code (900) and use the message from the caller.

# File lib/em/protocols/smtpclient.rb, line 226
def invoke_internal_error msg = "???"
  @return_values.elapsed_time = Time.now - @return_values.start_time
  @return_values.responder = @responder
  @return_values.code = 900
  @return_values.message = msg
  set_deferred_status :failed, @return_values
  send_data "QUIT\r\n"
  close_connection_after_writing
end
invoke_mail_from() click to toggle source
# File lib/em/protocols/smtpclient.rb, line 289
def invoke_mail_from
  send_data "MAIL FROM: <#{@args[:from]}>\r\n"
  @responder = :receive_mail_from_response
end
invoke_rcpt_to() click to toggle source
# File lib/em/protocols/smtpclient.rb, line 298
def invoke_rcpt_to
  @rcpt_responses ||= []
  l = @rcpt_responses.length
  to = @args[:to].is_a?(Array) ? @args[:to] : [@args[:to].to_s]
  if l < to.length
    send_data "RCPT TO: <#{to[l]}>\r\n"
    @responder = :receive_rcpt_to_response
  else
    e = @rcpt_responses.select {|rr| rr.last == 2}
    if e and e.length > 0
      invoke_data
    else
      invoke_error
    end
  end
end
invoke_starttls() click to toggle source
# File lib/em/protocols/smtpclient.rb, line 248
def invoke_starttls
  if @args[:starttls]
    # It would be more sociable to first ask if @server_caps contains
    # the string "STARTTLS" before we invoke it, but hey, life's too short.
    send_data "STARTTLS\r\n"
    @responder = :receive_starttls_response
  else
    invoke_auth
  end
end
receive_auth_response() click to toggle source
# File lib/em/protocols/smtpclient.rb, line 284
def receive_auth_response
  return invoke_error unless @range == 2
  invoke_mail_from
end
receive_data_response() click to toggle source
# File lib/em/protocols/smtpclient.rb, line 323
def receive_data_response
  return invoke_error unless @range == 3

  # The data to send can be given either in @args[:content] (an array or string of raw data
  # which MUST be in correct SMTP body format, including a trailing dot line), or a header and
  # body given in @args[:header] and @args[:body].
  #
  if @args[:content]
    send_data @args[:content].to_s
  else
    # The header can be a hash or an array.
    if @args[:header].is_a?(Hash)
      (@args[:header] || {}).each {|k,v| send_data "#{k}: #{v}\r\n" }
    else
      send_data @args[:header].to_s
    end
    send_data "\r\n"

    if @args[:body].is_a?(Array)
      @args[:body].each {|e| send_data e}
    else
      send_data @args[:body].to_s
    end

    send_data "\r\n.\r\n"
  end

  @responder = :receive_message_response
end
receive_ehlo_response() click to toggle source
# File lib/em/protocols/smtpclient.rb, line 242
def receive_ehlo_response
  return invoke_error unless @range == 2
  @server_caps = @msg
  invoke_starttls
end
receive_mail_from_response() click to toggle source
# File lib/em/protocols/smtpclient.rb, line 293
def receive_mail_from_response
  return invoke_error unless @range == 2
  invoke_rcpt_to
end
receive_message_response() click to toggle source
# File lib/em/protocols/smtpclient.rb, line 352
def receive_message_response
  return invoke_error unless @range == 2
  send_data "QUIT\r\n"
  close_connection_after_writing
  @succeeded = true
  @return_values.elapsed_time = Time.now - @return_values.start_time
  @return_values.responder = @responder
  @return_values.code = @code
  @return_values.message = @msg
  set_deferred_status :succeeded, @return_values
end
receive_rcpt_to_response() click to toggle source
# File lib/em/protocols/smtpclient.rb, line 314
def receive_rcpt_to_response
  @rcpt_responses << [@code, @msg, @range]
  invoke_rcpt_to
end
receive_signon() click to toggle source
# File lib/em/protocols/smtpclient.rb, line 236
def receive_signon
  return invoke_error unless @range == 2
  send_data "EHLO #{@args[:domain]}\r\n"
  @responder = :receive_ehlo_response
end
receive_starttls_response() click to toggle source
# File lib/em/protocols/smtpclient.rb, line 258
def receive_starttls_response
  return invoke_error unless @range == 2
  start_tls
  invoke_auth
end