diff --git a/.reek.yml b/.reek.yml
index 7b9083b..58b070b 100644
--- a/.reek.yml
+++ b/.reek.yml
@@ -21,18 +21,21 @@ detectors:
   Attribute:
     exclude:
       - Truemail::Configuration#smtp_safe_check
-      - Truemail::Validate::ResolverExecutionWrapper#attempts
+      - Truemail::Wrapper#attempts
 
   UtilityFunction:
     exclude:
       - Truemail::Validate::Smtp::Request#compose_from
       - Truemail::Validator#select_validation_type
       - Truemail::Validate::Mx#null_mx?
+      - Truemail::Validate::Mx#a_record
+      - Truemail::Audit::Ptr#current_host_address
 
   ControlParameter:
     exclude:
       - Truemail::GenerateEmailHelper#calculate_email_size
-      - Truemail::Validate::Base#success
+      - Truemail::Worker#success
+      - Truemail#raise_unless
 
   FeatureEnvy:
     exclude:
diff --git a/Gemfile.lock b/Gemfile.lock
index 4d77e6e..b930cec 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    truemail (0.1.6)
+    truemail (0.1.7)
 
 GEM
   remote: https://rubygems.org/
diff --git a/README.md b/README.md
index 019a97e..7849dc0 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 [![Maintainability](https://api.codeclimate.com/v1/badges/657aa241399927dcd2e2/maintainability)](https://codeclimate.com/github/rubygarage/truemail/maintainability) [![Test Coverage](https://api.codeclimate.com/v1/badges/657aa241399927dcd2e2/test_coverage)](https://codeclimate.com/github/rubygarage/truemail/test_coverage) [![Gem Version](https://badge.fury.io/rb/truemail.svg)](https://badge.fury.io/rb/truemail) [![CircleCI](https://circleci.com/gh/rubygarage/truemail/tree/master.svg?style=svg)](https://circleci.com/gh/rubygarage/truemail/tree/master) [![Contributor Covenant](https://img.shields.io/badge/Contributor%20Covenant-v1.4%20adopted-ff69b4.svg)](CODE_OF_CONDUCT.md)
 
-The Truemail gem helps you validate emails by regex pattern, presence of domain mx-records, and real existence of email account on a current email server.
+The Truemail gem helps you validate emails by regex pattern, presence of domain mx-records, and real existence of email account on a current email server. Also Truemail gem allows performing an audit of the host in which runs.
 
 ## Features
 
@@ -137,7 +137,7 @@ Truemail.configuration
 
 #### Regex validation
 
-Validation with regex pattern is the first validation level. By default this validation not performs strictly following RFC 5322 standart, so you can override Truemail default regex pattern if you want.
+Validation with regex pattern is the first validation level. By default this validation not performs strictly following RFC 5322 standard, so you can override Truemail default regex pattern if you want.
 
 Example of usage:
 
@@ -383,6 +383,30 @@ Truemail.validate('email@example.com')
     @validation_type=:smtp>
 ```
 
+### Host audit features
+
+Truemail gem allows performing an audit of the host in which runs. Only PTR record audit performs for today.
+
+#### PTR audit
+
+So what is a PTR record? A PTR record, or pointer record, enables someone to perform a reverse DNS lookup. This allows them to determine your domain name based on your IP address. Because generic domain names without a PTR are often associated with spammers, incoming mail servers identify email from hosts without PTR records as spam and you can't verify yours emails qualitatively.
+
+```ruby
+Truemail.host_audit
+# Everything is good
+=> #<Truemail::Auditor:0x00005580df358828
+   @result=
+     #<struct Truemail::Auditor::Result
+       warnings={}>>
+
+# Has PTR warning
+=> #<Truemail::Auditor:0x00005580df358828
+   @result=
+     #<struct Truemail::Auditor::Result
+       warnings=
+         {:ptr=>"ptr record does not reference to current verifier domain"}>>
+```
+
 ### Truemail helpers
 
 #### .valid?
diff --git a/lib/truemail.rb b/lib/truemail.rb
index 28168cc..1f95699 100644
--- a/lib/truemail.rb
+++ b/lib/truemail.rb
@@ -1,9 +1,6 @@
 # frozen_string_literal: true
 
-require 'truemail/version'
 require 'truemail/core'
-require 'truemail/configuration'
-require 'truemail/validator'
 
 module Truemail
   INCOMPLETE_CONFIG = 'verifier_email is required parameter'
@@ -15,7 +12,7 @@ def configuration
         return unless block_given?
         configuration = Truemail::Configuration.new
         yield(configuration)
-        raise ConfigurationError, INCOMPLETE_CONFIG unless configuration.complete?
+        raise_unless(configuration.complete?, INCOMPLETE_CONFIG)
         configuration
       end
     end
@@ -29,12 +26,23 @@ def reset_configuration!
     end
 
     def validate(email, **options)
-      raise ConfigurationError, NOT_CONFIGURED unless configuration
+      raise_unless(configuration, NOT_CONFIGURED)
       Truemail::Validator.new(email, **options).run
     end
 
     def valid?(email, **options)
       validate(email, **options).result.valid?
     end
+
+    def host_audit
+      raise_unless(configuration, NOT_CONFIGURED)
+      Truemail::Auditor.run
+    end
+
+    private
+
+    def raise_unless(condition, message)
+      raise ConfigurationError, message unless condition
+    end
   end
 end
diff --git a/lib/truemail/audit/base.rb b/lib/truemail/audit/base.rb
new file mode 100644
index 0000000..994c290
--- /dev/null
+++ b/lib/truemail/audit/base.rb
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+module Truemail
+  module Audit
+    class Base < Truemail::Worker
+      private
+
+      def add_warning(message)
+        result.warnings[self.class.name.split('::').last.downcase.to_sym] = message
+      end
+    end
+  end
+end
diff --git a/lib/truemail/audit/ptr.rb b/lib/truemail/audit/ptr.rb
new file mode 100644
index 0000000..6f7bc95
--- /dev/null
+++ b/lib/truemail/audit/ptr.rb
@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+module Truemail
+  module Audit
+    class Ptr < Truemail::Audit::Base
+      require 'ipaddr'
+      require 'resolv'
+
+      NOT_FOUND = 'ptr record for current host address was not found'
+      NOT_REFERENCES = 'ptr record does not reference to current verifier domain'
+
+      def run
+        return if ptr_records.empty? && add_warning(Truemail::Audit::Ptr::NOT_FOUND)
+        return if ptr_references_to_verifier_domain?
+        add_warning(Truemail::Audit::Ptr::NOT_REFERENCES)
+      end
+
+      private
+
+      def current_host_address
+        Resolv.getaddress(Socket.gethostname)
+      end
+
+      def current_host_reverse_lookup
+        IPAddr.new(current_host_address).reverse
+      end
+
+      def ptr_records
+        @ptr_records ||= Truemail::Wrapper.call do
+          Resolv::DNS.new.getresources(
+            current_host_reverse_lookup, Resolv::DNS::Resource::IN::PTR
+          ).map { |ptr_record| ptr_record.name.to_s }
+        end || []
+      end
+
+      def ptr_references_to_verifier_domain?
+        ptr_records.include?(Truemail.configuration.verifier_domain)
+      end
+    end
+  end
+end
diff --git a/lib/truemail/auditor.rb b/lib/truemail/auditor.rb
new file mode 100644
index 0000000..6f9679d
--- /dev/null
+++ b/lib/truemail/auditor.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module Truemail
+  class Auditor
+    Result = Struct.new(:warnings, keyword_init: true) do
+      def initialize(warnings: {}, **args)
+        super
+      end
+    end
+
+    def self.run
+      new.run
+    end
+
+    def result
+      @result ||= Truemail::Auditor::Result.new
+    end
+
+    def run
+      Truemail::Audit::Ptr.check(result)
+      self
+    end
+  end
+end
diff --git a/lib/truemail/core.rb b/lib/truemail/core.rb
index 23b33d2..85c08f1 100644
--- a/lib/truemail/core.rb
+++ b/lib/truemail/core.rb
@@ -1,6 +1,13 @@
 # frozen_string_literal: true
 
 module Truemail
+  require 'truemail/version'
+  require 'truemail/configuration'
+  require 'truemail/worker'
+  require 'truemail/wrapper'
+  require 'truemail/auditor'
+  require 'truemail/validator'
+
   class ConfigurationError < StandardError; end
 
   class ArgumentError < StandardError
@@ -16,10 +23,14 @@ module RegexConstant
     REGEX_DOMAIN_FROM_EMAIL = /\A.+@(.+)\z/
   end
 
+  module Audit
+    require 'truemail/audit/base'
+    require 'truemail/audit/ptr'
+  end
+
   module Validate
     require 'truemail/validate/base'
     require 'truemail/validate/regex'
-    require 'truemail/validate/resolver_execution_wrapper'
     require 'truemail/validate/mx'
     require 'truemail/validate/smtp'
     require 'truemail/validate/smtp/response'
diff --git a/lib/truemail/validate/base.rb b/lib/truemail/validate/base.rb
index a009c6a..0adfb6a 100644
--- a/lib/truemail/validate/base.rb
+++ b/lib/truemail/validate/base.rb
@@ -2,23 +2,9 @@
 
 module Truemail
   module Validate
-    class Base
-      attr_reader :result
-
-      def self.check(result)
-        new(result).run
-      end
-
-      def initialize(result)
-        @result = result
-      end
-
+    class Base < Truemail::Worker
       private
 
-      def success(condition)
-        result.success = condition || false
-      end
-
       def add_error(message)
         result.errors[self.class.name.split('::').last.downcase.to_sym] = message
       end
diff --git a/lib/truemail/validate/mx.rb b/lib/truemail/validate/mx.rb
index ca385cf..77d2d78 100644
--- a/lib/truemail/validate/mx.rb
+++ b/lib/truemail/validate/mx.rb
@@ -24,7 +24,7 @@ def host_extractor_methods
 
       def mx_lookup
         host_extractor_methods.any? do |method|
-          Truemail::Validate::ResolverExecutionWrapper.call { send(method) }
+          Truemail::Wrapper.call { send(method) }
         end
       end
 
@@ -41,8 +41,8 @@ def domain_not_include_null_mx
         !mail_servers.include?(Truemail::Validate::Mx::NULL_MX_RECORD)
       end
 
-      def mx_records(domain)
-        domain_mx_records = Resolv::DNS.new.getresources(domain, Resolv::DNS::Resource::IN::MX)
+      def mx_records(hostname)
+        domain_mx_records = Resolv::DNS.new.getresources(hostname, Resolv::DNS::Resource::IN::MX)
         return [Truemail::Validate::Mx::NULL_MX_RECORD] if null_mx?(domain_mx_records)
         domain_mx_records.sort_by(&:preference).map do |mx_record|
           Resolv.getaddresses(mx_record.exchange.to_s)
@@ -53,16 +53,24 @@ def mail_servers_found?
         !mail_servers.empty?
       end
 
+      def domain
+        result.domain
+      end
+
       def hosts_from_mx_records?
-        fetch_target_hosts(mx_records(result.domain))
+        fetch_target_hosts(mx_records(domain))
         mail_servers_found?
       end
 
+      def a_record(hostname)
+        Resolv.getaddress(hostname)
+      end
+
       def hosts_from_cname_records?
-        cname_records = Resolv::DNS.new.getresources(result.domain, Resolv::DNS::Resource::IN::CNAME)
+        cname_records = Resolv::DNS.new.getresources(domain, Resolv::DNS::Resource::IN::CNAME)
         return if cname_records.empty?
         cname_records.each do |cname_record|
-          host = Resolv.getaddress(cname_record.name.to_s)
+          host = a_record(cname_record.name.to_s)
           hostname = Resolv.getname(host)
           found_hosts = mx_records(hostname)
           fetch_target_hosts(found_hosts.empty? ? [host] : found_hosts)
@@ -71,7 +79,7 @@ def hosts_from_cname_records?
       end
 
       def host_from_a_record?
-        fetch_target_hosts([Resolv.getaddress(result.domain)])
+        fetch_target_hosts([a_record(domain)])
         mail_servers_found?
       end
     end
diff --git a/lib/truemail/validate/resolver_execution_wrapper.rb b/lib/truemail/validate/resolver_execution_wrapper.rb
deleted file mode 100644
index 16b8d89..0000000
--- a/lib/truemail/validate/resolver_execution_wrapper.rb
+++ /dev/null
@@ -1,26 +0,0 @@
-# frozen_string_literal: true
-
-module Truemail
-  module Validate
-    class ResolverExecutionWrapper
-      attr_accessor :attempts
-
-      def self.call(&block)
-        new.call(&block)
-      end
-
-      def initialize
-        @attempts = Truemail.configuration.connection_attempts
-      end
-
-      def call(&block)
-        Timeout.timeout(Truemail.configuration.connection_timeout, &block)
-      rescue Resolv::ResolvError
-        false
-      rescue Timeout::Error
-        retry unless (self.attempts -= 1).zero?
-        false
-      end
-    end
-  end
-end
diff --git a/lib/truemail/validate/smtp.rb b/lib/truemail/validate/smtp.rb
index 4947845..5c3dd36 100644
--- a/lib/truemail/validate/smtp.rb
+++ b/lib/truemail/validate/smtp.rb
@@ -4,7 +4,7 @@ module Truemail
   module Validate
     class Smtp < Truemail::Validate::Base
       ERROR = 'smtp error'
-      ERROR_BODY = /(?=.*550)(?=.*(user|account)).*/i
+      ERROR_BODY = /(?=.*550)(?=.*(user|account|customer|mailbox)).*/i
 
       attr_reader :smtp_results
 
diff --git a/lib/truemail/version.rb b/lib/truemail/version.rb
index b1c74cd..be60ec9 100644
--- a/lib/truemail/version.rb
+++ b/lib/truemail/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Truemail
-  VERSION = '0.1.6'
+  VERSION = '0.1.7'
 end
diff --git a/lib/truemail/worker.rb b/lib/truemail/worker.rb
new file mode 100644
index 0000000..9decd3a
--- /dev/null
+++ b/lib/truemail/worker.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+module Truemail
+  class Worker
+    attr_reader :result
+
+    def self.check(result)
+      new(result).run
+    end
+
+    def initialize(result)
+      @result = result
+    end
+
+    private
+
+    def success(condition)
+      result.success = condition || false
+    end
+  end
+end
diff --git a/lib/truemail/wrapper.rb b/lib/truemail/wrapper.rb
new file mode 100644
index 0000000..350483f
--- /dev/null
+++ b/lib/truemail/wrapper.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module Truemail
+  class Wrapper
+    attr_accessor :attempts
+
+    def self.call(&block)
+      new.call(&block)
+    end
+
+    def initialize
+      @attempts = Truemail.configuration.connection_attempts
+    end
+
+    def call(&block)
+      Timeout.timeout(Truemail.configuration.connection_timeout, &block)
+    rescue Resolv::ResolvError
+      false
+    rescue Timeout::Error
+      retry unless (self.attempts -= 1).zero?
+      false
+    end
+  end
+end
diff --git a/spec/truemail/audit/ptr_spec.rb b/spec/truemail/audit/ptr_spec.rb
new file mode 100644
index 0000000..17dc652
--- /dev/null
+++ b/spec/truemail/audit/ptr_spec.rb
@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+
+RSpec.describe Truemail::Audit::Ptr do
+  let(:email) { FFaker::Internet.email }
+  let(:result_instance) { Truemail::Auditor::Result.new }
+
+  before { Truemail.configure { |config| config.verifier_email = email } }
+
+  describe 'defined constants' do
+    specify { expect(described_class).to be_const_defined(:NOT_FOUND) }
+    specify { expect(described_class).to be_const_defined(:NOT_REFERENCES) }
+  end
+
+  describe '.check' do
+    subject(:ptr_auditor) { described_class.check(result_instance) }
+
+    let(:ptr_auditor_instance) { instance_double(described_class, run: true) }
+
+    it 'receive #run' do
+      allow(described_class).to receive(:new).and_return(ptr_auditor_instance)
+      expect(ptr_auditor_instance).to receive(:run)
+      expect(ptr_auditor).to be(true)
+    end
+  end
+
+  describe '#run' do
+    subject(:ptr_auditor) { ptr_auditor_instance.run }
+
+    let(:ptr_auditor_instance) { described_class.new(result_instance) }
+    let(:host_name) { Truemail.configuration.verifier_domain }
+    let(:other_host_name) { 'localhost' }
+
+    before do
+      allow(Socket).to receive(:gethostname).and_return(other_host_name)
+      allow(Resolv).to receive(:getaddress).and_return(FFaker::Internet.ip_v4_address)
+    end
+
+    context 'when ptr record exists and refereces to verifier domain' do
+      it 'not changes warnings' do
+        expect(Resolv::DNS).to receive_message_chain(:new, :getresources, :map).and_return([host_name])
+        expect { ptr_auditor }.to not_change(result_instance, :warnings)
+      end
+    end
+
+    context 'when ptr record for current host address was not found' do
+      it 'addes not found warning' do
+        expect(Resolv::DNS).to receive_message_chain(:new, :getresources, :map).and_return([])
+        expect { ptr_auditor }.to change(result_instance, :warnings).from({}).to({ ptr: Truemail::Audit::Ptr::NOT_FOUND })
+      end
+    end
+
+    context 'when ptr record checking crashes' do
+      it 'addes not found warning' do
+        expect(Resolv::DNS).to receive_message_chain(:new, :getresources, :map).and_raise(Resolv::ResolvError)
+        expect { ptr_auditor }.to change(result_instance, :warnings).from({}).to({ ptr: Truemail::Audit::Ptr::NOT_FOUND })
+      end
+    end
+
+    context 'when ptr record does not reference to current verifier domain' do
+      it 'addes not references warning' do
+        expect(Resolv::DNS).to receive_message_chain(:new, :getresources, :map).and_return([other_host_name])
+        expect { ptr_auditor }.to change(result_instance, :warnings).from({}).to({ ptr: Truemail::Audit::Ptr::NOT_REFERENCES })
+      end
+    end
+  end
+end
diff --git a/spec/truemail/auditor_spec.rb b/spec/truemail/auditor_spec.rb
new file mode 100644
index 0000000..7703e04
--- /dev/null
+++ b/spec/truemail/auditor_spec.rb
@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+module Truemail
+  RSpec.describe Truemail::Auditor do
+    subject(:auditor_instance) { described_class.run }
+
+    let(:email) { FFaker::Internet.email }
+    let(:auditor_instance_result) { auditor_instance.result }
+
+    before { Truemail.configure { |config| config.verifier_email = email } }
+
+    describe 'defined constants' do
+      specify { expect(described_class).to be_const_defined(:Result) }
+    end
+
+    describe '.run' do
+      it 'creates and updates default auditor result' do
+        allow(Truemail::Audit::Ptr).to receive(:check)
+        expect(auditor_instance).to be_an_instance_of(Truemail::Auditor)
+        expect(auditor_instance_result).to be_an_instance_of(Truemail::Auditor::Result)
+        expect(auditor_instance_result.warnings).to eq({})
+      end
+    end
+  end
+
+  RSpec.describe Truemail::Auditor::Result do
+    subject(:result_instance) { described_class.new }
+
+    let(:hash_object) { {} }
+
+    specify do
+      expect(result_instance.members).to include(:warnings)
+    end
+
+    it 'has default values for attributes' do
+      expect(result_instance.warnings).to eq(hash_object)
+    end
+
+    it 'accepts parametrized arguments' do
+      expect(described_class.new(warnings: hash_object).warnings).to eq(hash_object)
+    end
+  end
+end
diff --git a/spec/truemail/validate/resolver_execution_wrapper_spec.rb b/spec/truemail/wrapper_spec.rb
similarity index 96%
rename from spec/truemail/validate/resolver_execution_wrapper_spec.rb
rename to spec/truemail/wrapper_spec.rb
index 3fac12d..da4035a 100644
--- a/spec/truemail/validate/resolver_execution_wrapper_spec.rb
+++ b/spec/truemail/wrapper_spec.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-RSpec.describe Truemail::Validate::ResolverExecutionWrapper do
+RSpec.describe Truemail::Wrapper do
   let(:email) { FFaker::Internet.email }
   let(:method) { :hosts_from_mx_records? }
   let(:mx_instance) { instance_double(Truemail::Validate::Mx, method => true) }
diff --git a/spec/truemail_spec.rb b/spec/truemail_spec.rb
index 2d6e419..993fb56 100644
--- a/spec/truemail_spec.rb
+++ b/spec/truemail_spec.rb
@@ -4,14 +4,19 @@
   let(:email) { FFaker::Internet.email }
 
   describe 'defined constants' do
-    specify { expect(described_class).to be_const_defined(:VERSION) }
     specify { expect(described_class).to be_const_defined(:INCOMPLETE_CONFIG) }
     specify { expect(described_class).to be_const_defined(:NOT_CONFIGURED) }
+    specify { expect(described_class).to be_const_defined(:VERSION) }
+    specify { expect(described_class).to be_const_defined(:Configuration) }
+    specify { expect(described_class).to be_const_defined(:Worker) }
+    specify { expect(described_class).to be_const_defined(:Wrapper) }
+    specify { expect(described_class).to be_const_defined(:Auditor) }
+    specify { expect(described_class).to be_const_defined(:Validator) }
     specify { expect(described_class).to be_const_defined(:ConfigurationError) }
     specify { expect(described_class).to be_const_defined(:ArgumentError) }
     specify { expect(described_class).to be_const_defined(:RegexConstant) }
-    specify { expect(described_class).to be_const_defined(:Configuration) }
-    specify { expect(described_class).to be_const_defined(:Validator) }
+    specify { expect(described_class).to be_const_defined(:Audit) }
+    specify { expect(described_class).to be_const_defined(:Validate) }
   end
 
   describe '.configure' do
@@ -139,10 +144,28 @@
 
     before { described_class.configure { |config| config.verifier_email = email } }
 
-    it 'returns boolean from result instance' do
+    it 'returns boolean from validator result instance' do
       allow(Truemail::Validate::Smtp).to receive(:check).and_return(true)
       allow_any_instance_of(Truemail::Validator::Result).to receive(:valid?).and_return(true)
       expect(valid_helper).to be(true)
     end
   end
+
+  describe '.host_audit' do
+    subject(:host_audit) { described_class.host_audit }
+
+    before do
+      described_class.configure { |config| config.verifier_email = email }
+      allow(Truemail::Auditor).to receive(:run).and_call_original
+    end
+
+    it 'returns auditor instance' do
+      expect(host_audit).to be_an_instance_of(Truemail::Auditor)
+    end
+
+    it 'runs checks for auditor result instance' do
+      expect(Truemail::Audit::Ptr).to receive(:check)
+      host_audit
+    end
+  end
 end