Class: Net::SMTP

Inherits:
Object
  • Object
show all
Defined in:
lib/net/smtp.rb

Overview

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 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 = "From: Your Name <[email protected]>\nTo: Destination Address <[email protected]>\nSubject: test message\nDate: Sat, 23 Jun 2001 16:26:43 +0900\nMessage-Id: <[email protected]>\n\nThis is a test message.\n"

require 'net/smtp'
Net::SMTP.start('your.smtp.server', 25) do |smtp|
  smtp.send_message msgstr,
                    '[email protected]',
                    '[email protected]'
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, '[email protected]', '[email protected]'
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, '[email protected]', '[email protected]'
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)

Constant Summary collapse

Revision =
%q$Revision: 28208 $.split[1]
DEFAULT_AUTH_TYPE =
:plain

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(address, port = nil) ⇒ SMTP

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.


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# File '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_occured = false
  @debug_output = nil
  @tls = false
  @starttls = false
  @ssl_context = nil
end

Instance Attribute Details

#addressObject (readonly)

The address of the SMTP server to connect to.


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# File 'lib/net/smtp.rb', line 366

def address
  @address
end

#open_timeoutObject

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


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# File 'lib/net/smtp.rb', line 374

def open_timeout
  @open_timeout
end

#portObject (readonly)

The port number of the SMTP server to connect to.


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# File 'lib/net/smtp.rb', line 369

def port
  @port
end

#read_timeoutObject

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.


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# File 'lib/net/smtp.rb', line 379

def read_timeout
  @read_timeout
end

Class Method Details

.default_portObject

The default SMTP port number, 25.


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# File 'lib/net/smtp.rb', line 178

def SMTP.default_port
  25
end

.default_ssl_contextObject


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# File 'lib/net/smtp.rb', line 196

def SMTP.default_ssl_context
  OpenSSL::SSL::SSLContext.new
end

.default_submission_portObject

The default mail submission port number, 587.


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# File 'lib/net/smtp.rb', line 183

def SMTP.default_submission_port
  587
end

.default_tls_portObject Also known as: default_ssl_port

The default SMTPS port number, 465.


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# File 'lib/net/smtp.rb', line 188

def SMTP.default_tls_port
  465
end

.start(address, port = nil, helo = 'localhost.localdomain', user = nil, secret = nil, authtype = nil, &block) ⇒ Object

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

This method is equivalent to:

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

Example

Net::SMTP.start('your.smtp.server') do |smtp|
  smtp.send_message msgstr, '[email protected]', ['[email protected]']
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


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# File 'lib/net/smtp.rb', line 460

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

Instance Method Details

#auth_cram_md5(user, secret) ⇒ Object


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# File 'lib/net/smtp.rb', line 746

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

#auth_login(user, secret) ⇒ Object


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# File 'lib/net/smtp.rb', line 735

def (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

#auth_plain(user, secret) ⇒ Object


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# File 'lib/net/smtp.rb', line 726

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

#authenticate(user, secret, authtype = DEFAULT_AUTH_TYPE) ⇒ Object


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# File 'lib/net/smtp.rb', line 720

def authenticate(user, secret, authtype = DEFAULT_AUTH_TYPE)
  check_auth_method authtype
  check_auth_args user, secret
  send auth_method(authtype), user, secret
end

#capable_auth_typesObject

Returns supported authentication methods on this server. You cannot get valid value before opening SMTP session.


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# File 'lib/net/smtp.rb', line 289

def capable_auth_types
  return [] unless @capabilities
  return [] unless @capabilities['AUTH']
  @capabilities['AUTH']
end

#capable_cram_md5_auth?Boolean

true if server advertises AUTH CRAM-MD5. You cannot get valid value before opening SMTP session.


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# File 'lib/net/smtp.rb', line 276

def capable_cram_md5_auth?
  auth_capable?('CRAM-MD5')
end

#capable_login_auth?Boolean

true if server advertises AUTH LOGIN. You cannot get valid value before opening SMTP session.


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# File 'lib/net/smtp.rb', line 270

def 
  auth_capable?('LOGIN')
end

#capable_plain_auth?Boolean

true if server advertises AUTH PLAIN. You cannot get valid value before opening SMTP session.


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# File 'lib/net/smtp.rb', line 264

def capable_plain_auth?
  auth_capable?('PLAIN')
end

#capable_starttls?Boolean

true if server advertises STARTTLS. You cannot get valid value before opening SMTP session.


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# File 'lib/net/smtp.rb', line 252

def capable_starttls?
  capable?('STARTTLS')
end

#data(msgstr = nil, &block) ⇒ Object

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("From: [email protected]\nTo: [email protected]\nSubject: I found a bug\n\nCheck vm.c:58879.\n")

# Example 2 (by block)
smtp.data {|f|
  f.puts "From: [email protected]"
  f.puts "To: [email protected]"
  f.puts "Subject: I found a bug"
  f.puts ""
  f.puts "Check vm.c:58879."
}

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# File 'lib/net/smtp.rb', line 880

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

#debug_output=(arg) ⇒ Object Also known as: set_debug_output

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

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# File 'lib/net/smtp.rb', line 402

def debug_output=(arg)
  @debug_output = arg
end

#disable_starttlsObject

Disables SMTP/TLS (STARTTLS) for this object. Must be called before the connection is established to have any effect.


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# File 'lib/net/smtp.rb', line 360

def disable_starttls
  @starttls = false
  @ssl_context = nil
end

#disable_tlsObject Also known as: disable_ssl

Disables SMTP/TLS for this object. Must be called before the connection is established to have any effect.


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# File 'lib/net/smtp.rb', line 316

def disable_tls
  @tls = false
  @ssl_context = nil
end

#ehlo(domain) ⇒ Object


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# File 'lib/net/smtp.rb', line 818

def ehlo(domain)
  getok("EHLO #{domain}")
end

#enable_starttls(context = SMTP.default_ssl_context) ⇒ Object

Enables SMTP/TLS (STARTTLS) for this object. context is a OpenSSL::SSL::SSLContext object.

Raises:

  • (ArgumentError)

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# File 'lib/net/smtp.rb', line 342

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

#enable_starttls_auto(context = SMTP.default_ssl_context) ⇒ Object

Enables SMTP/TLS (STARTTLS) for this object if server accepts. context is a OpenSSL::SSL::SSLContext object.

Raises:

  • (ArgumentError)

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# File 'lib/net/smtp.rb', line 351

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

#enable_tls(context = SMTP.default_ssl_context) ⇒ Object Also known as: enable_ssl

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.

Raises:

  • (ArgumentError)

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# File 'lib/net/smtp.rb', line 305

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

#esmtp=(bool) ⇒ Object

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).


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# File 'lib/net/smtp.rb', line 244

def esmtp=(bool)
  @esmtp = bool
end

#esmtp?Boolean Also known as: esmtp

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


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# File 'lib/net/smtp.rb', line 233

def esmtp?
  @esmtp
end

#finishObject

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

Raises:

  • (IOError)

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# File 'lib/net/smtp.rb', line 538

def finish
  raise IOError, 'not yet started' unless started?
  do_finish
end

#helo(domain) ⇒ Object


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# File 'lib/net/smtp.rb', line 814

def helo(domain)
  getok("HELO #{domain}")
end

#inspectObject

Provide human-readable stringification of class state.


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# File 'lib/net/smtp.rb', line 228

def inspect
  "#<#{self.class} #{@address}:#{@port} started=#{@started}>"
end

#mailfrom(from_addr) ⇒ Object


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# File 'lib/net/smtp.rb', line 822

def mailfrom(from_addr)
  if $SAFE > 0
    raise SecurityError, 'tainted from_addr' if from_addr.tainted?
  end
  getok("MAIL FROM:<#{from_addr}>")
end

#open_message_stream(from_addr, *to_addrs, &block) ⇒ Object Also known as: ready

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('[email protected]', ['[email protected]']) do |f|
    f.puts 'From: [email protected]'
    f.puts 'To: [email protected]'
    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

Raises:

  • (IOError)

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# File 'lib/net/smtp.rb', line 704

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

#quitObject


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# File 'lib/net/smtp.rb', line 900

def quit
  getok('QUIT')
end

#rcptto(to_addr) ⇒ Object


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# File 'lib/net/smtp.rb', line 850

def rcptto(to_addr)
  if $SAFE > 0
    raise SecurityError, 'tainted to_addr' if to_addr.tainted?
  end
  getok("RCPT TO:<#{to_addr}>")
end

#rcptto_list(to_addrs) ⇒ Object

Raises:

  • (ArgumentError)

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# File 'lib/net/smtp.rb', line 829

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

#send_message(msgstr, from_addr, *to_addrs) ⇒ Object Also known as: send_mail, sendmail

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,
                    '[email protected]',
                    ['[email protected]', '[email protected]']
end

Errors

This method may raise:

  • Net::SMTPServerBusy

  • Net::SMTPSyntaxError

  • Net::SMTPFatalError

  • Net::SMTPUnknownError

  • IOError

  • TimeoutError

Raises:

  • (IOError)

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# File 'lib/net/smtp.rb', line 651

def send_message(msgstr, from_addr, *to_addrs)
  raise IOError, 'closed session' unless @socket
  mailfrom from_addr
  rcptto_list(to_addrs) {data msgstr}
end

#start(helo = 'localhost.localdomain', user = nil, secret = nil, authtype = nil) ⇒ Object

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, , password, authtype) do |smtp|
  smtp.send_message msgstr, '[email protected]', ['[email protected]']
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


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# File 'lib/net/smtp.rb', line 521

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?Boolean

true if the SMTP session has been started.


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# File 'lib/net/smtp.rb', line 467

def started?
  @started
end

#starttlsObject


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# File 'lib/net/smtp.rb', line 810

def starttls
  getok('STARTTLS')
end

#starttls?Boolean

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.


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# File 'lib/net/smtp.rb', line 326

def starttls?
  @starttls
end

#starttls_always?Boolean

true if this object uses STARTTLS.


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# File 'lib/net/smtp.rb', line 331

def starttls_always?
  @starttls == :always
end

#starttls_auto?Boolean

true if this object uses STARTTLS when server advertises STARTTLS.


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# File 'lib/net/smtp.rb', line 336

def starttls_auto?
  @starttls == :auto
end

#tls?Boolean Also known as: ssl?

true if this object uses SMTP/TLS (SMTPS).


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# File 'lib/net/smtp.rb', line 296

def tls?
  @tls
end