Module: Sisimai::RFC3834

Defined in:
lib/sisimai/rfc3834.rb

Overview

Sisimai::RFC3834 - RFC3834 auto reply message detector

Constant Summary collapse

MarkingsOf =

tools.ietf.org/html/rfc3834

{:boundary => '__SISIMAI_PSEUDO_BOUNDARY__'}
LowerLabel = 
%w[from to subject auto-submitted precedence x-apple-action].freeze
DoNotParse = 
{
  'from'    => ['root@', 'postmaster@', 'mailer-daemon@'],
  'to'      => ['root@'],
  'subject' => [
      'security information for', # sudo(1)
      'mail failure -',           # Exim
  ],
}.freeze
AutoReply0 = 
{
  # http://www.iana.org/assignments/auto-submitted-keywords/auto-submitted-keywords.xhtml
  'auto-submitted' => ['auto-generated', 'auto-replied', 'auto-notified'],
  'precedence'     => ['auto_reply'],
  'subject'        => ['auto:', 'auto response:', 'automatic reply:', 'out of office:', 'out of the office:'],
  'x-apple-action' => ['vacation'],
}.freeze
SubjectSet = 
%r{\A(?>
   (?:.+?)?re:
  |auto(?:[ ]response):
  |automatic[ ]reply:
  |out[ ]of[ ]office:
  )
  [ ]*(.+)\z
}x.freeze
Suspending = 
[
  ["this email inbox", " is no longer in use."],
].freeze

Class Method Summary collapse

Class Method Details

.description ⇒ Object 



138
 
# File 'lib/sisimai/rfc3834.rb', line 138

def description; 'Detector for auto replied message'; end

.inquire(mhead, mbody) ⇒ Hash, Nil

Detect auto reply message as RFC3834

Parameters:

  • mhead (Hash) —

    Message headers of a bounce email

  • mbody (String) —

    Message body of a bounce email

Returns:

  • (Hash) —

    Bounce data list and message/rfc822 part

  • (Nil) —

    it failed to decode or the arguments are missing



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# File 'lib/sisimai/rfc3834.rb', line 40

def inquire(mhead, mbody)
  leave = 0
  match = 0
  lower = {} 

  LowerLabel.each do |e|
    # Set lower-cased value of each header related to auto-response
    next if mhead.has_key?(e) == false
    lower[e] = mhead[e].downcase
  end

  # DETECT_EXCLUSION_MESSAGE
  DoNotParse.each_key do |e|
    # Exclude message from root@
    next if lower[e].nil? || DoNotParse[e].none? { |a| lower[e].include?(a) }
    leave = 1
    break
  end
  return nil if leave > 0

  # DETECT_AUTO_REPLY_MESSAGE0
  AutoReply0.each_key do |e|
    # RFC3834 Auto-Submitted and other headers
    next if lower[e].nil? || AutoReply0[e].none? { |a| lower[e].include?(a) }
    match += 1
    break
  end
  return nil if match < 1

  require 'sisimai/lhost'
  dscontents = [Sisimai::Lhost.DELIVERYSTATUS]; v = dscontents[-1]
  bodyslices = mbody.scrub('?').split("\n")
  rfc822part = '' # (String) message/rfc822-headers part
  recipients = 0  # (Integer) The number of 'Final-Recipient' header
  maxmsgline = 5  # (Integer) Max message length(lines)
  haveloaded = 0  # (Integer) The number of lines loaded from message body
  blanklines = 0  # (Integer) Counter for countinuous blank lines
  countuntil = 1  # (Integer) Maximum value of blank lines in the body part

  # RECIPIENT_ADDRESS
  %w[from return-path].each do |e|
    # Try to get the address of the recipient
    next if mhead[e].nil?
    v['recipient'] = mhead[e]
    break
  end

  if v["recipient"] != ""
    # Clean-up the recipient address
    v['recipient'] = Sisimai::Address.s3s4(v['recipient'])
    recipients += 1
  end
  return nil if recipients == 0

  if mhead['content-type']
    # Get the boundary string and set regular expression for matching with the boundary string.
    q = Sisimai::RFC2045.boundary(mhead['content-type'], 0) || ''
    MarkingsOf[:boundary] = q if q.empty? == false
  end

  # MESSAGE_BODY: Get the vacation message
  while e = bodyslices.shift do
    # Read the first 5 lines except a blank line
    countuntil += 1 if e.include?(MarkingsOf[:boundary])

    if e.empty?
      # Check a blank line
      blanklines += 1
      break if blanklines > countuntil
      next
    end
    next if !e.include?(' ') || e.start_with?('Content-Type', 'Content-Transfer')

    v['diagnosis'] ||= ''
    v['diagnosis']  += "#{e }"
    haveloaded += 1
    break if haveloaded >= maxmsgline
  end
  v['diagnosis'] ||= mhead['subject']
  v['reason']      = 'vacation'

  cv = v['diagnosis'].downcase
  Suspending.each do |e|
    # Check that the auto-replied message indicates the "Suspend" reason or not.
    next unless Sisimai::String.aligned(cv, e)
    v['reason'] = 'suspend'
    break
  end

  v['date']   = mhead['date']
  v['status'] = ''

  if cv = lower['subject'].match(SubjectSet)
    # Get the Subject header from the original message
    rfc822part = "Subject: #{cv[1]}\n"
  end
  return { 'ds' => dscontents, 'rfc822' => rfc822part }
end