class 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 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 ::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 ::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 ::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 ::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
- CRAM_BUFSIZE
- DEFAULT_AUTH_TYPE
Authentication
- IMASK
- OMASK
- Revision
Attributes
The address of the SMTP server to connect to.
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.
The port number of the SMTP server to connect to.
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.
Public Class Methods
The default SMTP port number, 25.
# File lib/net/smtp.rb, line 177 def SMTP.default_port 25 end
# File lib/net/smtp.rb, line 195 def SMTP.default_ssl_context OpenSSL::SSL::SSLContext.new end
The default mail submission port number, 587.
# File lib/net/smtp.rb, line 182 def SMTP.default_submission_port 587 end
The default SMTPS port number, 465.
# File lib/net/smtp.rb, line 187 def SMTP.default_tls_port 465 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 ::start instead of ::new if you want to do everything at once. Otherwise, follow ::new with #start.
# File lib/net/smtp.rb, line 210 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 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 lib/net/smtp.rb, line 454 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
Public Instance Methods
# File lib/net/smtp.rb, line 755 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 lib/net/smtp.rb, line 744 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 lib/net/smtp.rb, line 735 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 lib/net/smtp.rb, line 729 def authenticate(user, secret, authtype = DEFAULT_AUTH_TYPE) check_auth_method authtype check_auth_args user, secret send auth_method(authtype), user, secret end
Returns supported authentication methods on this server. You cannot get valid value before opening SMTP session.
# File lib/net/smtp.rb, line 282 def capable_auth_types return [] unless @capabilities return [] unless @capabilities['AUTH'] @capabilities['AUTH'] end
true if server advertises AUTH CRAM-MD5. You cannot get valid value before opening SMTP session.
# File lib/net/smtp.rb, line 269 def capable_cram_md5_auth? auth_capable?('CRAM-MD5') end
true if server advertises AUTH LOGIN. You cannot get valid value before opening SMTP session.
# File lib/net/smtp.rb, line 263 def capable_login_auth? auth_capable?('LOGIN') end
true if server advertises AUTH PLAIN. You cannot get valid value before opening SMTP session.
# File lib/net/smtp.rb, line 257 def capable_plain_auth? auth_capable?('PLAIN') end
true if server advertises STARTTLS. You cannot get valid value before opening SMTP session.
# File lib/net/smtp.rb, line 245 def capable_starttls? capable?('STARTTLS') 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("From: john@example.com To: betty@example.com Subject: I found a bug Check vm.c:58879. ") # 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 lib/net/smtp.rb, line 889 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
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 lib/net/smtp.rb, line 395 def debug_output=(arg) @debug_output = arg end
Disables SMTP/TLS (STARTTLS) for this object. Must be called before the connection is established to have any effect.
# File lib/net/smtp.rb, line 353 def disable_starttls @starttls = false @ssl_context = nil end
Disables SMTP/TLS for this object. Must be called before the connection is established to have any effect.
# File lib/net/smtp.rb, line 309 def disable_tls @tls = false @ssl_context = nil end
# File lib/net/smtp.rb, line 827 def ehlo(domain) getok("EHLO #{domain}") end
Enables SMTP/TLS (STARTTLS) for this object. context
is a OpenSSL::SSL::SSLContext object.
# File lib/net/smtp.rb, line 335 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.
# File lib/net/smtp.rb, line 344 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 (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 lib/net/smtp.rb, line 298 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
# File lib/net/smtp.rb, line 823 def helo(domain) getok("HELO #{domain}") end
Provide human-readable stringification of class state.
# File lib/net/smtp.rb, line 227 def inspect "#<#{self.class} #{@address}:#{@port} started=#{@started}>" end
# File lib/net/smtp.rb, line 831 def mailfrom(from_addr) if $SAFE > 0 raise SecurityError, 'tainted from_addr' if from_addr.tainted? end getok("MAIL FROM:<#{from_addr}>") 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 lib/net/smtp.rb, line 713 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
# File lib/net/smtp.rb, line 909 def quit getok('QUIT') end
# File lib/net/smtp.rb, line 859 def rcptto(to_addr) if $SAFE > 0 raise SecurityError, 'tainted to_addr' if to_addr.tainted? end getok("RCPT TO:<#{to_addr}>") end
# File lib/net/smtp.rb, line 838 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
Set the number of seconds to wait until timing-out a read(2) call.
# File lib/net/smtp.rb, line 376 def read_timeout=(sec) @socket.read_timeout = sec if @socket @read_timeout = sec 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 lib/net/smtp.rb, line 660 def send_message(msgstr, from_addr, *to_addrs) raise IOError, 'closed session' unless @socket mailfrom from_addr rcptto_list(to_addrs) {data msgstr} 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 ::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 lib/net/smtp.rb, line 516 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
true
if the SMTP session has been
started.
# File lib/net/smtp.rb, line 461 def started? @started end
SMTP command dispatcher
# File lib/net/smtp.rb, line 819 def starttls getok('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 lib/net/smtp.rb, line 319 def starttls? @starttls end
true if this object uses STARTTLS.
# File lib/net/smtp.rb, line 324 def starttls_always? @starttls == :always end
true if this object uses STARTTLS when server advertises STARTTLS.
# File lib/net/smtp.rb, line 329 def starttls_auto? @starttls == :auto end
true if this object uses SMTP/TLS (SMTPS).
# File lib/net/smtp.rb, line 289 def tls? @tls end
Private Instance Methods
# File lib/net/smtp.rb, line 273 def auth_capable?(type) return nil unless @capabilities return false unless @capabilities['AUTH'] @capabilities['AUTH'].include?(type) end
# File lib/net/smtp.rb, line 775 def auth_method(type) "auth_#{type.to_s.downcase}".intern end
# File lib/net/smtp.rb, line 788 def base64_encode(str) # expects "str" may not become too long [str].pack('m').gsub(/\s+/, '') end
# File lib/net/smtp.rb, line 249 def capable?(key) return nil unless @capabilities @capabilities[key] ? true : false end
# File lib/net/smtp.rb, line 779 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 lib/net/smtp.rb, line 967 def check_auth_continue(res) unless res.continue? raise res.exception_class, res.message end end
# File lib/net/smtp.rb, line 769 def check_auth_method(type) unless respond_to?(auth_method(type), true) raise ArgumentError, "wrong authentication type #{type}" end end
# File lib/net/smtp.rb, line 961 def check_auth_response(res) unless res.success? raise SMTPAuthenticationError, res.message end end
# File lib/net/smtp.rb, line 955 def check_continue(res) unless res.continue? raise SMTPUnknownError, "could not get 3xx (#{res.status}: #{res.string})" end end
# File lib/net/smtp.rb, line 949 def check_response(res) unless res.success? raise res.exception_class, res.message end end
CRAM-MD5: [RFC2195]
# File lib/net/smtp.rb, line 797 def cram_md5_response(secret, challenge) tmp = Digest::MD5.digest(cram_secret(secret, IMASK) + challenge) Digest::MD5.hexdigest(cram_secret(secret, OMASK) + tmp) end
# File lib/net/smtp.rb, line 804 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 lib/net/smtp.rb, line 939 def critical return Response.parse('200 dummy reply code') if @error_occurred begin return yield() rescue Exception @error_occurred = true raise end end
# File lib/net/smtp.rb, line 615 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 lib/net/smtp.rb, line 603 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 lib/net/smtp.rb, line 544 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 lib/net/smtp.rb, line 924 def get_response(reqline) @socket.writeline reqline recv_response() end
# File lib/net/smtp.rb, line 915 def getok(reqline) res = critical { @socket.writeline reqline recv_response() } check_response res res end
# File lib/net/smtp.rb, line 1052 def logging(msg) @debug_output << msg + "\n" if @debug_output end
# File lib/net/smtp.rb, line 596 def new_internet_message_io(s) io = InternetMessageIO.new(s) io.read_timeout = @read_timeout io.debug_output = @debug_output io end
# File lib/net/smtp.rb, line 929 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 lib/net/smtp.rb, line 577 def ssl_socket(socket, context) OpenSSL::SSL::SSLSocket.new socket, context end
# File lib/net/smtp.rb, line 540 def tcp_socket(address, port) TCPSocket.open address, port end
# File lib/net/smtp.rb, line 581 def tlsconnect(s) verified = false s = ssl_socket(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 verified = true s ensure s.close unless verified end