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# = net/smtp.rb
#
# Copyright (c) 1999-2007 Yukihiro Matsumoto.
#
# Copyright (c) 1999-2007 Minero Aoki.
#
# Written & maintained by Minero Aoki <aamine@loveruby.net>.
#
# Documented by William Webber and Minero Aoki.
#
# This program is free software. You can re-distribute and/or
# modify this program under the same terms as Ruby itself.
#
# NOTE: You can find Japanese version of this document at:
# http://www.ruby-lang.org/ja/man/html/net_smtp.html
#
# $Id$
#
# See Net::SMTP for documentation.
#
require 'net/protocol'
require 'digest/md5'
require 'timeout'
begin
require 'openssl'
rescue LoadError
end
module Net
# Module mixed in to all SMTP error classes
module SMTPError
# This *class* is a module for backward compatibility.
# In later release, this module becomes a class.
end
# Represents an SMTP authentication error.
class SMTPAuthenticationError < ProtoAuthError
include SMTPError
end
# Represents SMTP error code 420 or 450, a temporary error.
class SMTPServerBusy < ProtoServerError
include SMTPError
end
# Represents an SMTP command syntax error (error code 500)
class SMTPSyntaxError < ProtoSyntaxError
include SMTPError
end
# Represents a fatal SMTP error (error code 5xx, except for 500)
class SMTPFatalError < ProtoFatalError
include SMTPError
end
# Unexpected reply code returned from server.
class SMTPUnknownError < ProtoUnknownError
include SMTPError
end
# Command is not supported on server.
class SMTPUnsupportedCommand < ProtocolError
include SMTPError
end
#
# = 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] (http://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.
# (http://www.ruby-lang.org/en/raa.html)
#
# FYI: the official documentation on internet mail is: [RFC2822] (http://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 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 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 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
# 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)
#
class SMTP
# The default SMTP port number, 25.
def SMTP.default_port
25
end
# The default mail submission port number, 587.
def SMTP.default_submission_port
587
end
# The default SMTPS port number, 465.
def SMTP.default_tls_port
465
end
class << self
alias default_ssl_port default_tls_port
end
def SMTP.default_ssl_context
OpenSSL::SSL::SSLContext.new
end
#
# 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
# SMTP.start instead of SMTP.new if you want to do everything
# at once. Otherwise, follow SMTP.new with SMTP#start.
#
def initialize(address, port = nil)
@address = address
@port = (port || SMTP.default_port)
@esmtp = true
@capabilities = nil
@socket = nil
@started = false
@open_timeout = 30
@read_timeout = 60
@error_occured = false
@debug_output = nil
@tls = false
@starttls = false
@ssl_context = nil
end
# Provide human-readable stringification of class state.
def inspect
"#<#{self.class} #{@address}:#{@port} started=#{@started}>"
end
# +true+ if the SMTP object uses ESMTP (which it does by default).
def esmtp?
@esmtp
end
#
# 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).
#
def esmtp=(bool)
@esmtp = bool
end
alias esmtp esmtp?
# true if server advertises STARTTLS.
# You cannot get valid value before opening SMTP session.
def capable_starttls?
capable?('STARTTLS')
end
def capable?(key)
return nil unless @capabilities
@capabilities[key] ? true : false
end
private :capable?
# true if server advertises AUTH PLAIN.
# You cannot get valid value before opening SMTP session.
def capable_plain_auth?
auth_capable?('PLAIN')
end
# true if server advertises AUTH LOGIN.
# You cannot get valid value before opening SMTP session.
def capable_login_auth?
auth_capable?('LOGIN')
end
# true if server advertises AUTH CRAM-MD5.
# You cannot get valid value before opening SMTP session.
def capable_cram_md5_auth?
auth_capable?('CRAM-MD5')
end
def auth_capable?(type)
return nil unless @capabilities
return false unless @capabilities['AUTH']
@capabilities['AUTH'].include?(type)
end
private :auth_capable?
# Returns supported authentication methods on this server.
# You cannot get valid value before opening SMTP session.
def capable_auth_types
return [] unless @capabilities
return [] unless @capabilities['AUTH']
@capabilities['AUTH']
end
# true if this object uses SMTP/TLS (SMTPS).
def tls?
@tls
end
alias ssl? tls?
# Enables SMTP/TLS (SMTPS: SMTP over direct TLS connection) for
# this object. Must be called before the connection is established
# to have any effect. +context+ is a OpenSSL::SSL::SSLContext object.
def enable_tls(context = SMTP.default_ssl_context)
raise 'openssl library not installed' unless defined?(OpenSSL)
raise ArgumentError, "SMTPS and STARTTLS is exclusive" if @starttls
@tls = true
@ssl_context = context
end
alias enable_ssl enable_tls
# Disables SMTP/TLS for this object. Must be called before the
# connection is established to have any effect.
def disable_tls
@tls = false
@ssl_context = nil
end
alias disable_ssl disable_tls
# Returns truth value if this object uses STARTTLS.
# If this object always uses STARTTLS, returns :always.
# If this object uses STARTTLS when the server support TLS, returns :auto.
def starttls?
@starttls
end
# true if this object uses STARTTLS.
def starttls_always?
@starttls == :always
end
# true if this object uses STARTTLS when server advertises STARTTLS.
def starttls_auto?
@starttls == :auto
end
# Enables SMTP/TLS (STARTTLS) for this object.
# +context+ is a OpenSSL::SSL::SSLContext object.
def enable_starttls(context = SMTP.default_ssl_context)
raise 'openssl library not installed' unless defined?(OpenSSL)
raise ArgumentError, "SMTPS and STARTTLS is exclusive" if @tls
@starttls = :always
@ssl_context = context
end
# Enables SMTP/TLS (STARTTLS) for this object if server accepts.
# +context+ is a OpenSSL::SSL::SSLContext object.
def enable_starttls_auto(context = SMTP.default_ssl_context)
raise 'openssl library not installed' unless defined?(OpenSSL)
raise ArgumentError, "SMTPS and STARTTLS is exclusive" if @tls
@starttls = :auto
@ssl_context = context
end
# Disables SMTP/TLS (STARTTLS) for this object. Must be called
# before the connection is established to have any effect.
def disable_starttls
@starttls = false
@ssl_context = nil
end
# The address of the SMTP server to connect to.
attr_reader :address
# The port number of the SMTP server to connect to.
attr_reader :port
# Seconds to wait while attempting to open a connection.
# If the connection cannot be opened within this time, a
# TimeoutError is raised.
attr_accessor :open_timeout
# 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.
attr_reader :read_timeout
# Set the number of seconds to wait until timing-out a read(2)
# call.
def read_timeout=(sec)
@socket.read_timeout = sec if @socket
@read_timeout = sec
end
#
# 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
#
def debug_output=(arg)
@debug_output = arg
end
alias set_debug_output debug_output=
#
# SMTP session control
#
#
# 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:
#
# * Net::SMTPAuthenticationError
# * Net::SMTPServerBusy
# * Net::SMTPSyntaxError
# * Net::SMTPFatalError
# * Net::SMTPUnknownError
# * IOError
# * TimeoutError
#
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
# +true+ if the SMTP session has been started.
def started?
@started
end
#
# 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 SMTP.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 SMTP.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:
#
# * Net::SMTPAuthenticationError
# * Net::SMTPServerBusy
# * Net::SMTPSyntaxError
# * Net::SMTPFatalError
# * Net::SMTPUnknownError
# * IOError
# * TimeoutError
#
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
# Finishes the SMTP session and closes TCP connection.
# Raises IOError if not started.
def finish
raise IOError, 'not yet started' unless started?
do_finish
end
private
def do_start(helo_domain, user, secret, authtype)
raise IOError, 'SMTP session already started' if @started
if user or secret
check_auth_method(authtype || DEFAULT_AUTH_TYPE)
check_auth_args user, secret
end
s = timeout(@open_timeout) { TCPSocket.open(@address, @port) }
logging "Connection opened: #{@address}:#{@port}"
@socket = new_internet_message_io(tls? ? tlsconnect(s) : s)
check_response critical { recv_response() }
do_helo helo_domain
if starttls_always? or (capable_starttls? and starttls_auto?)
unless capable_starttls?
raise SMTPUnsupportedCommand,
"STARTTLS is not supported on this server"
end
starttls
@socket = new_internet_message_io(tlsconnect(s))
# helo response may be different after STARTTLS
do_helo helo_domain
end
authenticate user, secret, (authtype || DEFAULT_AUTH_TYPE) if user
@started = true
ensure
unless @started
# authentication failed, cancel connection.
s.close if s and not s.closed?
@socket = nil
end
end
def tlsconnect(s)
s = OpenSSL::SSL::SSLSocket.new(s, @ssl_context)
logging "TLS connection started"
s.sync_close = true
s.connect
if @ssl_context.verify_mode != OpenSSL::SSL::VERIFY_NONE
s.post_connection_check(@address)
end
s
end
def new_internet_message_io(s)
io = InternetMessageIO.new(s)
io.read_timeout = @read_timeout
io.debug_output = @debug_output
io
end
def do_helo(helo_domain)
res = @esmtp ? ehlo(helo_domain) : helo(helo_domain)
@capabilities = res.capabilities
rescue SMTPError
if @esmtp
@esmtp = false
@error_occured = false
retry
end
raise
end
def do_finish
quit if @socket and not @socket.closed? and not @error_occured
ensure
@started = false
@error_occured = false
@socket.close if @socket and not @socket.closed?
@socket = nil
end
#
# Message Sending
#
public
#
# 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:
#
# * Net::SMTPServerBusy
# * Net::SMTPSyntaxError
# * Net::SMTPFatalError
# * Net::SMTPUnknownError
# * IOError
# * TimeoutError
#
def send_message(msgstr, from_addr, *to_addrs)
raise IOError, 'closed session' unless @socket
mailfrom from_addr
rcptto_list to_addrs
data msgstr
end
alias send_mail send_message
alias sendmail send_message # obsolete
#
# 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:
#
# * Net::SMTPServerBusy
# * Net::SMTPSyntaxError
# * Net::SMTPFatalError
# * Net::SMTPUnknownError
# * IOError
# * TimeoutError
#
def open_message_stream(from_addr, *to_addrs, &block) # :yield: stream
raise IOError, 'closed session' unless @socket
mailfrom from_addr
rcptto_list to_addrs
data(&block)
end
alias ready open_message_stream # obsolete
#
# Authentication
#
public
DEFAULT_AUTH_TYPE = :plain unless const_defined?(:DEFAULT_AUTH_TYPE)
def authenticate(user, secret, authtype = DEFAULT_AUTH_TYPE)
check_auth_method authtype
check_auth_args user, secret
send auth_method(authtype), user, secret
end
def auth_plain(user, secret)
check_auth_args user, secret
res = critical {
get_response('AUTH PLAIN ' + base64_encode("\0#{user}\0#{secret}"))
}
check_auth_response res
res
end
def auth_login(user, secret)
check_auth_args user, secret
res = critical {
check_auth_continue get_response('AUTH LOGIN')
check_auth_continue get_response(base64_encode(user))
get_response(base64_encode(secret))
}
check_auth_response res
res
end
def auth_cram_md5(user, secret)
check_auth_args user, secret
res = critical {
res0 = get_response('AUTH CRAM-MD5')
check_auth_continue res0
crammed = cram_md5_response(secret, res0.cram_md5_challenge)
get_response(base64_encode("#{user} #{crammed}"))
}
check_auth_response res
res
end
private
def check_auth_method(type)
unless respond_to?(auth_method(type), true)
raise ArgumentError, "wrong authentication type #{type}"
end
end
def auth_method(type)
"auth_#{type.to_s.downcase}".intern
end
def check_auth_args(user, secret)
unless user
raise ArgumentError, 'SMTP-AUTH requested but missing user name'
end
unless secret
raise ArgumentError, 'SMTP-AUTH requested but missing secret phrase'
end
end
def base64_encode(str)
# expects "str" may not become too long
[str].pack('m').gsub(/\s+/, '')
end
IMASK = 0x36 unless const_defined?(:IMASK)
OMASK = 0x5c unless const_defined?(:OMASK)
# CRAM-MD5: [RFC2195]
def cram_md5_response(secret, challenge)
tmp = Digest::MD5.digest(cram_secret(secret, IMASK) + challenge)
Digest::MD5.hexdigest(cram_secret(secret, OMASK) + tmp)
end
CRAM_BUFSIZE = 64 unless const_defined?(:CRAM_BUFSIZE)
def cram_secret(secret, mask)
secret = Digest::MD5.digest(secret) if secret.size > CRAM_BUFSIZE
buf = secret.ljust(CRAM_BUFSIZE, "\0")
0.upto(buf.size - 1) do |i|
buf[i] = (buf[i].ord ^ mask).chr
end
buf
end
#
# SMTP command dispatcher
#
public
def starttls
getok('STARTTLS')
end
def helo(domain)
getok("HELO #{domain}")
end
def ehlo(domain)
getok("EHLO #{domain}")
end
def mailfrom(from_addr)
if $SAFE > 0
raise SecurityError, 'tainted from_addr' if from_addr.tainted?
end
getok("MAIL FROM:<#{from_addr}>")
end
def rcptto_list(to_addrs)
raise ArgumentError, 'mail destination not given' if to_addrs.empty?
to_addrs.flatten.each do |addr|
rcptto addr
end
end
def rcptto(to_addr)
if $SAFE > 0
raise SecurityError, 'tainted to_addr' if to_addr.tainted?
end
getok("RCPT TO:<#{to_addr}>")
end
# This method sends a message.
# If +msgstr+ is given, sends it as a message.
# If block is given, yield a message writer stream.
# You must write message before the block is closed.
#
# # Example 1 (by string)
# smtp.data(<<EndMessage)
# From: john@example.com
# To: betty@example.com
# Subject: I found a bug
#
# Check vm.c:58879.
# EndMessage
#
# # Example 2 (by block)
# smtp.data {|f|
# f.puts "From: john@example.com"
# f.puts "To: betty@example.com"
# f.puts "Subject: I found a bug"
# f.puts ""
# f.puts "Check vm.c:58879."
# }
#
def data(msgstr = nil, &block) #:yield: stream
if msgstr and block
raise ArgumentError, "message and block are exclusive"
end
unless msgstr or block
raise ArgumentError, "message or block is required"
end
res = critical {
check_continue get_response('DATA')
if msgstr
@socket.write_message msgstr
else
@socket.write_message_by_block(&block)
end
recv_response()
}
check_response res
res
end
def quit
getok('QUIT')
end
private
def getok(reqline)
res = critical {
@socket.writeline reqline
recv_response()
}
check_response res
res
end
def get_response(reqline)
@socket.writeline reqline
recv_response()
end
def recv_response
buf = ''
while true
line = @socket.readline
buf << line << "\n"
break unless line[3,1] == '-' # "210-PIPELINING"
end
Response.parse(buf)
end
def critical(&block)
return '200 dummy reply code' if @error_occured
begin
return yield()
rescue Exception
@error_occured = true
raise
end
end
def check_response(res)
unless res.success?
raise res.exception_class, res.message
end
end
def check_continue(res)
unless res.continue?
raise SMTPUnknownError, "could not get 3xx (#{res.status})"
end
end
def check_auth_response(res)
unless res.success?
raise SMTPAuthenticationError, res.message
end
end
def check_auth_continue(res)
unless res.continue?
raise res.exception_class, res.message
end
end
class Response
def Response.parse(str)
new(str[0,3], str)
end
def initialize(status, string)
@status = status
@string = string
end
attr_reader :status
attr_reader :string
def status_type_char
@status[0, 1]
end
def success?
status_type_char() == '2'
end
def continue?
status_type_char() == '3'
end
def message
@string.lines.first
end
def cram_md5_challenge
@string.split(/ /)[1].unpack('m')[0]
end
def capabilities
return {} unless @string[3, 1] == '-'
h = {}
@string.lines.drop(1).each do |line|
k, *v = line[4..-1].chomp.split(nil)
h[k] = v
end
h
end
def exception_class
case @status
when /\A4/ then SMTPServerBusy
when /\A50/ then SMTPSyntaxError
when /\A53/ then SMTPAuthenticationError
when /\A5/ then SMTPFatalError
else SMTPUnknownError
end
end
end
def logging(msg)
@debug_output << msg + "\n" if @debug_output
end
end # class SMTP
SMTPSession = SMTP unless const_defined?(:SMTPSession)
end