diff --git a/Gemfile b/Gemfile
index e51b66ac2b..5e79a594df 100644
--- a/Gemfile
+++ b/Gemfile
@@ -17,7 +17,7 @@ gem 'figaro', '~> 1.2'
 
 # model related
 gem 'paper_trail', '~> 14.0'
-gem 'pg', '1.5.7'
+gem 'pg', '1.5.6'
 # 1.8 is for Rails < 5.0
 gem 'ransack', '~> 4.0.0'
 gem 'truemail', '~> 3.0' # validates email by regexp, mail server existence and address existence
@@ -43,7 +43,7 @@ gem 'data_migrate', '~> 9.0'
 gem 'dnsruby', '~> 1.61'
 gem 'isikukood' # for EE-id validation
 gem 'money-rails'
-gem 'simpleidn', '0.2.3' # For punycode
+gem 'simpleidn', '0.2.2' # For punycode
 gem 'whenever', '1.0.0', require: false
 
 # country listing
@@ -78,7 +78,9 @@ gem 'rexml'
 gem 'wkhtmltopdf-binary', '~> 0.12.6.1'
 
 gem 'directo', github: 'internetee/directo', branch: 'master'
-
+gem 'net-ftp'
+gem 'net-pop'
+gem 'net-imap'
 gem 'strong_migrations'
 
 group :development, :test do
diff --git a/Gemfile.lock b/Gemfile.lock
index e4195ae935..1fcbeaf6cd 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -211,6 +211,7 @@ GEM
       activerecord (>= 5.a)
       database_cleaner-core (~> 2.0.0)
     database_cleaner-core (2.0.1)
+    date (3.3.4)
     devise (4.8.0)
       bcrypt (~> 3.0)
       orm_adapter (~> 0.1)
@@ -293,7 +294,7 @@ GEM
       activerecord
       kaminari-core (= 1.2.1)
     kaminari-core (1.2.1)
-    libxml-ruby (3.2.1)
+    libxml-ruby (5.0.3)
     logger (1.4.3)
     loofah (2.21.4)
       crass (~> 1.0.2)
@@ -322,6 +323,14 @@ GEM
       money (~> 6.13.2)
       railties (>= 3.0)
     msgpack (1.7.2)
+    net-ftp (0.3.7)
+      net-protocol
+      time
+    net-imap (0.4.14)
+      date
+      net-protocol
+    net-pop (0.1.2)
+      net-protocol
     net-protocol (0.1.3)
       timeout
     net-smtp (0.3.3)
@@ -361,7 +370,7 @@ GEM
       activerecord (>= 6.0)
       request_store (~> 1.4)
     pdfkit (0.8.7.2)
-    pg (1.5.7)
+    pg (1.5.6)
     pg_query (2.1.2)
       google-protobuf (>= 3.17.1)
     pghero (3.1.0)
@@ -469,7 +478,8 @@ GEM
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
-    simpleidn (0.2.3)
+    simpleidn (0.2.2)
+      unf (~> 0.1.4)
     sixarm_ruby_unaccent (1.2.0)
     socksify (1.7.1)
     sprockets (4.0.3)
@@ -490,6 +500,8 @@ GEM
     temple (0.8.2)
     thor (1.2.2)
     tilt (2.0.11)
+    time (0.3.0)
+      date
     timeout (0.3.0)
     truemail (3.0.3)
       simpleidn (~> 0.2.1)
@@ -572,6 +584,9 @@ DEPENDENCIES
   minitest (~> 5.17)
   minitest-stub_any_instance
   money-rails
+  net-ftp
+  net-imap
+  net-pop
   newrelic-infinite_tracing
   newrelic_rpm
   nokogiri (~> 1.16.0)
@@ -579,7 +594,7 @@ DEPENDENCIES
   omniauth-tara!
   paper_trail (~> 14.0)
   pdfkit
-  pg (= 1.5.7)
+  pg (= 1.5.6)
   pg_query (>= 0.9.0)
   pghero
   pry (= 0.14.2)
@@ -595,7 +610,7 @@ DEPENDENCIES
   selenium-webdriver
   sidekiq (~> 7.0)
   simplecov (= 0.17.1)
-  simpleidn (= 0.2.3)
+  simpleidn (= 0.2.2)
   spy
   strong_migrations
   truemail (~> 3.0)
@@ -606,4 +621,4 @@ DEPENDENCIES
   wkhtmltopdf-binary (~> 0.12.6.1)
 
 BUNDLED WITH
-   2.5.4
+   2.5.17
diff --git a/app/jobs/retry_greylisted_emails_job.rb b/app/jobs/retry_greylisted_emails_job.rb
new file mode 100644
index 0000000000..ed2f715dfd
--- /dev/null
+++ b/app/jobs/retry_greylisted_emails_job.rb
@@ -0,0 +1,82 @@
+class RetryGreylistedEmailsJob < ApplicationJob
+  queue_as :default
+
+  MAX_RETRY_ATTEMPTS = 10
+  INITIAL_RETRY_DELAY = 5.minutes
+
+  def perform
+    unique_greylisted_contacts.each do |contact|
+      retry_count = 0
+      success = false
+
+      while retry_count < MAX_RETRY_ATTEMPTS && !success
+        success = retry_email_validation(contact, retry_count)
+        retry_count += 1
+        sleep(calculate_delay(retry_count)) unless success
+      end
+
+      if success
+        clear_and_save_successful_validation(contact)
+      else
+        mark_email_as_invalid(contact)
+      end
+    end
+  end
+
+  private
+
+  def unique_greylisted_contacts
+    ValidationEvent.greylisted_smtp_errors
+      .select(:validation_eventable_id, :validation_eventable_type)
+      .distinct
+      .map(&:validation_eventable)
+  end
+
+  def retry_email_validation(contact, retry_count)
+    result = Truemail.validate(contact.email, with: :smtp).result
+    
+    contact.validation_events.create(
+      event_type: :email_validation,
+      success: result.success?,
+      event_data: {
+        check_level: 'smtp',
+        error: result.error,
+        retry_count: retry_count
+      }
+    )
+
+    result.success?
+  end
+
+  def calculate_delay(retry_count)
+    INITIAL_RETRY_DELAY * (2 ** (retry_count - 1))
+  end
+
+  def clear_and_save_successful_validation(contact)
+    contact.validation_events.destroy_all
+    contact.validation_events.create(
+      event_type: :email_validation,
+      success: true,
+      event_data: { check_level: 'smtp' }
+    )
+  end
+
+  def mark_email_as_invalid(contact)
+    contact.validation_events.destroy_all
+    contact.validation_events.create(
+      event_type: :email_validation,
+      success: false,
+      event_data: {
+        check_level: 'smtp',
+        error: 'Max retry count exceeded'
+      }
+    )
+  end
+
+  # Prevents sleep in test environment
+  def sleep(seconds)
+    return if Rails.env.test?
+    
+    super
+  end
+end
\ No newline at end of file
diff --git a/app/models/validation_event.rb b/app/models/validation_event.rb
index 80327f7c2a..f5dcfe93f1 100644
--- a/app/models/validation_event.rb
+++ b/app/models/validation_event.rb
@@ -10,6 +10,8 @@ class ValidationEvent < ApplicationRecord
   VALID_CHECK_LEVELS = %w[regex mx smtp].freeze
   VALID_EVENTS_COUNT_THRESHOLD = 5
   MX_CHECK = 3
+  MAX_RETRY_COUNT = 10
+  INITIAL_RETRY_DELAY = 5.minutes
 
   INVALID_EVENTS_COUNT_BY_LEVEL = {
     regex: 1,
@@ -34,6 +36,13 @@ class ValidationEvent < ApplicationRecord
   scope :mx, -> { where('event_data @> ?', { 'check_level': 'mx' }.to_json) }
   scope :smtp, -> { where('event_data @> ?', { 'check_level': 'smtp' }.to_json) }
   scope :by_object, ->(object) { where(validation_eventable: object) }
+  scope :greylisted_smtp_errors, -> {
+    where(success: false)
+      .where("event_data->>'check_level' = ?", 'smtp')
+      .where("event_data->'smtp_debug'->0->'response'->'errors'->>'rcptto' LIKE ?", '%Greylisted for%')
+      .where('created_at > ?', 24.hours.ago)
+  }
+
 
   def self.validated_ids_by(klass)
     old_records
@@ -50,6 +59,10 @@ def successful?
     success
   end
 
+  def greylisted?
+    event_type == 'smtp' && event_data['error'].include?('Greylisted for')
+  end
+
   def event_type
     @event_type ||= ValidationEvent::EventType.new(self[:event_type])
   end
diff --git a/test/jobs/retry_greylisted_emails_job_test.rb b/test/jobs/retry_greylisted_emails_job_test.rb
new file mode 100644
index 0000000000..cc868f08fd
--- /dev/null
+++ b/test/jobs/retry_greylisted_emails_job_test.rb
@@ -0,0 +1,141 @@
+require 'test_helper'
+
+class RetryGreylistedEmailsJobTest < ActiveJob::TestCase
+  def setup
+    @contact = contacts(:john)
+    @contact.validation_events.destroy_all
+    @greylisted_event = ValidationEvent.create(
+      validation_eventable: @contact,
+      event_type: :email_validation,
+      success: false,
+      event_data: {
+        email: @contact.email,
+        domain: @contact.email.split('@').last,
+        mail_servers: ["194.19.134.80", "185.138.56.208"],
+        errors: { smtp: "smtp error" },
+        smtp_debug: [{
+          host: "194.19.134.80",
+          email: @contact.email,
+          attempts: nil,
+          response: {
+            port_opened: true,
+            connection: true,
+            helo: true,
+            mailfrom: { status: "250", string: "250 2.1.0 Ok\n" },
+            rcptto: false,
+            errors: { rcptto: "451 4.7.1 <#{@contact.email}>: Recipient address rejected: Greylisted for 1 minutes\n" }
+          },
+          configuration: {
+            smtp_port: 25,
+            verifier_email: "no-reply@example.com",
+            verifier_domain: "example.com",
+            response_timeout: 1,
+            connection_timeout: 1
+          }
+        }],
+        check_level: "smtp"
+      }
+    )
+    @contact.reload
+  end
+
+  test 'performs retry for greylisted emails and succeeds' do
+    mock_truemail_success do
+      assert_no_difference 'ValidationEvent.count' do
+        RetryGreylistedEmailsJob.perform_now
+      end
+    end
+  
+    @contact.reload
+    assert @contact.validation_events.last.success?
+    assert_nil @contact.validation_events.last.event_data.dig('smtp_debug', 0, 'response', 'errors', 'rcptto')
+  end
+  
+  def test_marks_email_as_invalid_after_max_retries
+    mock_truemail_failure(RetryGreylistedEmailsJob::MAX_RETRY_ATTEMPTS) do
+      assert_no_difference 'ValidationEvent.count' do
+        RetryGreylistedEmailsJob.perform_now
+      end
+    end
+  
+    @contact.reload
+    last_event = @contact.validation_events.last
+    refute last_event.success?
+    
+    error_message = last_event.event_data['errors']&.dig('smtp') ||
+                    last_event.event_data['error'] ||
+                    last_event.event_data.dig('smtp_debug', 0, 'response', 'errors', 'rcptto')
+    
+    assert_equal 'Max retry count exceeded', error_message
+  end
+  
+  test 'retries until email is not greylisted' do
+    mock_truemail_success_after_failures(3) do
+      assert_no_difference 'ValidationEvent.count' do
+        RetryGreylistedEmailsJob.perform_now
+      end
+    end
+  
+    @contact.reload
+    assert @contact.validation_events.last.success?
+    assert_nil @contact.validation_events.last.event_data.dig('smtp_debug', 0, 'response', 'errors', 'rcptto')
+  end
+
+  private
+
+  def mock_truemail_success
+  result = mock_truemail_result(true)
+  Truemail.stub :validate, result do
+    yield if block_given?
+  end
+end
+
+def mock_truemail_failure(times = 1)
+  results = Array.new(times) { mock_truemail_result(false) }
+  Truemail.stub :validate, ->(*args) { results.shift || mock_truemail_result(false) } do
+    yield if block_given?
+  end
+end
+
+def mock_truemail_success_after_failures(failure_count)
+  results = Array.new(failure_count) { mock_truemail_result(false) }
+  results << mock_truemail_result(true)
+  Truemail.stub :validate, ->(*args) { results.shift || mock_truemail_result(true) } do
+    yield if block_given?
+  end
+end
+
+def mock_truemail_result(success)
+  OpenStruct.new(
+    result: OpenStruct.new(
+      success?: success,
+      email: @contact.email,
+      domain: @contact.email.split('@').last,
+      mail_servers: ["194.19.134.80", "185.138.56.208"],
+      errors: success ? {} : { smtp: "smtp error" },
+      smtp_debug: [
+        OpenStruct.new(
+          host: "194.19.134.80",
+          email: @contact.email,
+          attempts: nil,
+          response: OpenStruct.new(
+            port_opened: true,
+            connection: true,
+            helo: true,
+            mailfrom: OpenStruct.new(status: "250", string: "250 2.1.0 Ok\n"),
+            rcptto: success,
+            errors: success ? {} : { rcptto: "451 4.7.1 <#{@contact.email}>: Recipient address rejected: Greylisted for 1 minutes\n" }
+          ),
+          configuration: OpenStruct.new(
+            smtp_port: 25,
+            verifier_email: "no-reply@example.com",
+            verifier_domain: "example.com",
+            response_timeout: 1,
+            connection_timeout: 1
+          )
+        )
+      ]
+    )
+  )
+end
+end
\ No newline at end of file