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 or search for alternatives in RubyGems.org or The Ruby Toolbox.
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 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_address@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)
Authentication
Seconds to wait while attempting to open a connection. If the connection cannot be opened within this time, a Net::OpenTimeout is raised. The default value is 30 seconds.
Seconds to wait while reading one block (by one read(2) call). If the read(2) call does not complete within this time, a Net::ReadTimeout is raised. The default value is 60 seconds.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 178
def SMTP.default_port
  25
end
          
        
      The default SMTP port number, 25.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 196
def SMTP.default_ssl_context
  OpenSSL::SSL::SSLContext.new
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 183
def SMTP.default_submission_port
  587
end
          
        
      The default mail submission port number, 587.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 188
def SMTP.default_tls_port
  465
end
          
        
      The default SMTPS port number, 465.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 211
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_occurred = false
  @debug_output = nil
  @tls = false
  @starttls = false
  @ssl_context = nil
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.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 455
def SMTP.start(address, port = nil, helo = 'localhost',
               user = nil, secret = nil, authtype = nil,
               &block)   # :yield: smtp
  new(address, port).start(helo, user, secret, authtype, &block)
end
          
        
      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’.
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 tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 274
def auth_capable?(type)
  return nil unless @capabilities
  return false unless @capabilities['AUTH']
  @capabilities['AUTH'].include?(type)
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 756
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
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 745
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
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 776
def auth_method(type)
  "auth_#{type.to_s.downcase}".intern
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 736
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
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 730
def authenticate(user, secret, authtype = DEFAULT_AUTH_TYPE)
  check_auth_method authtype
  check_auth_args user, secret
  send auth_method(authtype), user, secret
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 789
def base64_encode(str)
  # expects "str" may not become too long
  [str].pack('m').gsub(/\s+/, '')
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 250
def capable?(key)
  return nil unless @capabilities
  @capabilities[key] ? true : false
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 283
def capable_auth_types
  return [] unless @capabilities
  return [] unless @capabilities['AUTH']
  @capabilities['AUTH']
end
          
        
      Returns supported authentication methods on this server. You cannot get valid value before opening SMTP session.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 270
def capable_cram_md5_auth?
  auth_capable?('CRAM-MD5')
end
          
        
      true if server advertises AUTH CRAM-MD5. You cannot get valid value before opening SMTP session.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 264
def capable_login_auth?
  auth_capable?('LOGIN')
end
          
        
      true if server advertises AUTH LOGIN. You cannot get valid value before opening SMTP session.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 258
def capable_plain_auth?
  auth_capable?('PLAIN')
end
          
        
      true if server advertises AUTH PLAIN. You cannot get valid value before opening SMTP session.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 246
def capable_starttls?
  capable?('STARTTLS')
end
          
        
      true if server advertises STARTTLS. You cannot get valid value before opening SMTP session.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 780
def check_auth_args(user, secret, authtype = DEFAULT_AUTH_TYPE)
  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
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 990
def check_auth_continue(res)
  unless res.continue?
    raise res.exception_class, res.message
  end
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 770
def check_auth_method(type)
  unless respond_to?(auth_method(type), true)
    raise ArgumentError, "wrong authentication type #{type}"
  end
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 984
def check_auth_response(res)
  unless res.success?
    raise SMTPAuthenticationError, res.message
  end
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 978
def check_continue(res)
  unless res.continue?
    raise SMTPUnknownError, "could not get 3xx (#{res.status}: #{res.string})"
  end
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 972
def check_response(res)
  unless res.success?
    raise res.exception_class, res.message
  end
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 798
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-MD5: [RFC2195]
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 805
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
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 962
def critical
  return Response.parse('200 dummy reply code') if @error_occurred
  begin
    return yield()
  rescue Exception
    @error_occurred = true
    raise
  end
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 896
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')
    socket_sync_bak = @socket.io.sync
    begin
      @socket.io.sync = false
      if msgstr
        @socket.write_message msgstr
      else
        @socket.write_message_by_block(&block)
      end
    ensure
      @socket.io.flush
      @socket.io.sync = socket_sync_bak
    end
    recv_response()
  }
  check_response res
  res
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." }
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 396
def debug_output=(arg)
  @debug_output = arg
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 354
def disable_starttls
  @starttls = false
  @ssl_context = nil
end
          
        
      Disables SMTP/TLS (STARTTLS) for this object. Must be called before the connection is established to have any effect.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 310
def disable_tls
  @tls = false
  @ssl_context = nil
end
          
        
      Disables SMTP/TLS for this object. Must be called before the connection is established to have any effect.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 616
def do_finish
  quit if @socket and not @socket.closed? and not @error_occurred
ensure
  @started = false
  @error_occurred = false
  @socket.close if @socket and not @socket.closed?
  @socket = nil
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 604
def do_helo(helo_domain)
  res = @esmtp ? ehlo(helo_domain) : helo(helo_domain)
  @capabilities = res.capabilities
rescue SMTPError
  if @esmtp
    @esmtp = false
    @error_occurred = false
    retry
  end
  raise
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 545
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.timeout(@open_timeout, Net::OpenTimeout) do
    tcp_socket(@address, @port)
  end
  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
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 834
def ehlo(domain)
  getok("EHLO #{domain}")
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 336
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. context is a OpenSSL::SSL::SSLContext object.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 345
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
          
        
      Enables SMTP/TLS (STARTTLS) for this object if server accepts. context is a OpenSSL::SSL::SSLContext object.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 299
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
          
        
      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.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 534
def finish
  raise IOError, 'not yet started' unless started?
  do_finish
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 946
def get_response(reqline)
  validate_line reqline
  @socket.writeline reqline
  recv_response()
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 936
def getok(reqline)
  validate_line reqline
  res = critical {
    @socket.writeline reqline
    recv_response()
  }
  check_response res
  res
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 830
def helo(domain)
  getok("HELO #{domain}")
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 228
def inspect
  "#<#{self.class} #{@address}:#{@port} started=#{@started}>"
end
          
        
      Provide human-readable stringification of class state.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 1075
def logging(msg)
  @debug_output << msg + "\n" if @debug_output
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 838
def mailfrom(from_addr)
  if $SAFE > 0
    raise SecurityError, 'tainted from_addr' if from_addr.tainted?
  end
  getok("MAIL FROM:<#{from_addr}>")
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 597
def new_internet_message_io(s)
  io = InternetMessageIO.new(s)
  io.read_timeout = @read_timeout
  io.debug_output = @debug_output
  io
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 714
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
          
        
      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 tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 923
def quit
  getok('QUIT')
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 866
def rcptto(to_addr)
  if $SAFE > 0
    raise SecurityError, 'tainted to_addr' if to_addr.tainted?
  end
  getok("RCPT TO:<#{to_addr}>")
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 845
def rcptto_list(to_addrs)
  raise ArgumentError, 'mail destination not given' if to_addrs.empty?
  ok_users = []
  unknown_users = []
  to_addrs.flatten.each do |addr|
    begin
      rcptto addr
    rescue SMTPAuthenticationError
      unknown_users << addr.dump
    else
      ok_users << addr
    end
  end
  raise ArgumentError, 'mail destination not given' if ok_users.empty?
  ret = yield
  unless unknown_users.empty?
    raise SMTPAuthenticationError, "failed to deliver for #{unknown_users.join(', ')}"
  end
  ret
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 377
def read_timeout=(sec)
  @socket.read_timeout = sec if @socket
  @read_timeout = sec
end
          
        
      Set the number of seconds to wait until timing-out a read(2) call.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 952
def recv_response
  buf = ''
  while true
    line = @socket.readline
    buf << line << "\n"
    break unless line[3,1] == '-'   # "210-PIPELINING"
  end
  Response.parse(buf)
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 822
def rset
  getok('RSET')
end
          
        
      Aborts the current mail transaction
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 661
def send_message(msgstr, from_addr, *to_addrs)
  raise IOError, 'closed session' unless @socket
  mailfrom from_addr
  rcptto_list(to_addrs) {data msgstr}
end
          
        
      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 tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 578
def ssl_socket(socket, context)
  OpenSSL::SSL::SSLSocket.new socket, context
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 517
def start(helo = 'localhost',
          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
          
        
      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:
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 462
def started?
  @started
end
          
        
      true if the SMTP session has been started.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 826
def starttls
  getok('STARTTLS')
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 320
def starttls?
  @starttls
end
          
        
      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.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 325
def starttls_always?
  @starttls == :always
end
          
        
      true if this object uses STARTTLS.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 330
def starttls_auto?
  @starttls == :auto
end
          
        
      true if this object uses STARTTLS when server advertises STARTTLS.
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 541
def tcp_socket(address, port)
  TCPSocket.open address, port
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 290
def tls?
  @tls
end
          
        
      true if this object uses SMTP/TLS (SMTPS).
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 582
def tlsconnect(s)
  verified = false
  s = ssl_socket(s, @ssl_context)
  logging "TLS connection started"
  s.sync_close = true
  ssl_socket_connect(s, @open_timeout)
  if @ssl_context.verify_mode != OpenSSL::SSL::VERIFY_NONE
    s.post_connection_check(@address)
  end
  verified = true
  s
ensure
  s.close unless verified
end
          
        
      
          
            # File tmp/rubies/ruby-2.3.8/lib/net/smtp.rb, line 929
def validate_line(line)
  # A bare CR or LF is not allowed in RFC5321.
  if /[\r\n]/ =~ line
    raise ArgumentError, "A line must not contain CR or LF"
  end
end