diff --git a/app/lib/greylist_checker.rb b/app/lib/greylist_checker.rb
new file mode 100644
index 0000000000..e5585cd6d1
--- /dev/null
+++ b/app/lib/greylist_checker.rb
@@ -0,0 +1,110 @@
+require 'net/smtp'
+require 'resolv'
+
+class GreylistChecker
+  GREYLIST_CODES = ['450', '451', '452', '421', '471', '472']
+
+  DEFAULT_OPTIONS = {
+    max_attempts: 1,
+    retry_delay: 60,
+    sender_email: 'martin@internet.ee',
+    helo_domain: 'hole.ee',
+    debug: true
+  }
+
+  def initialize(email, options = {})
+    @email = email
+    @domain = email.split('@').last
+    @options = DEFAULT_OPTIONS.merge(options)
+    @debug = @options[:debug]
+  end
+
+  def check
+    mx_servers = get_mx_servers
+    debug_print("MX servers for #{@domain}: #{mx_servers.join(', ')}")
+    return { status: :error, message: "Failed to find MX servers" } if mx_servers.empty?
+
+    mx_servers.each do |mx_server|
+      result = check_server(mx_server)
+      return result unless result[:status] == :greylisted
+    end
+
+    { status: :greylisted, message: "All attempts resulted in greylisting" }
+  end
+
+  private
+
+  def get_mx_servers
+    Resolv::DNS.open do |dns|
+      mx_records = dns.getresources(@domain, Resolv::DNS::Resource::IN::MX)
+      mx_records.sort_by(&:preference).map(&:exchange).map(&:to_s)
+    end
+  rescue => e
+    debug_print("Error getting MX servers: #{e.message}")
+    []
+  end
+
+  def check_server(mx_server)
+    attempts = 0
+    while attempts < @options[:max_attempts]
+      result = smtp_check(mx_server)
+      debug_print("Attempt #{attempts + 1} result: #{result}")
+      
+      return result unless result[:status] == :greylisted
+      
+      attempts += 1
+      if attempts < @options[:max_attempts]
+        debug_print("Waiting before next attempt: #{@options[:retry_delay]} seconds")
+        sleep @options[:retry_delay]
+      end
+    end
+    result
+  end
+
+  def smtp_check(mx_server)
+    debug_print("Starting SMTP check for server: #{mx_server}")
+    
+    Net::SMTP.start(mx_server, 25) do |smtp|
+      smtp.debug_output = method(:debug_print) if @debug
+      
+      debug_print("ehlo #{@options[:helo_domain]}")
+      smtp.ehlo(@options[:helo_domain])
+      
+      debug_print("mail from:<#{@options[:sender_email]}>")
+      smtp.mailfrom(@options[:sender_email])
+      
+      debug_print("rcpt to:<#{@email}>")
+      begin
+        response = smtp.rcptto(@email)
+        debug_print(response.message)
+        if response.success?
+          return { status: :success, message: "Email accepted" }
+        else
+          code = response.status.to_s[0..2]
+          if GREYLIST_CODES.include?(code)
+            return { status: :greylisted, message: "Greylisting detected: #{response.message}" }
+          else
+            return { status: :invalid, message: "Address rejected: #{response.message}" }
+          end
+        end
+      rescue Net::SMTPFatalError => e
+        debug_print("Received SMTP fatal error: #{e.message}")
+        return { status: :invalid, message: "Address rejected: #{e.message}" }
+      rescue Net::SMTPServerBusy => e
+        debug_print("Received SMTP Server Busy error: #{e.message}")
+        if GREYLIST_CODES.any? { |code| e.message.start_with?(code) }
+          return { status: :greylisted, message: "Greylisting detected: #{e.message}" }
+        else
+          return { status: :error, message: "Temporary server error: #{e.message}" }
+        end
+      end
+    end
+  rescue => e
+    debug_print("Error during SMTP check: #{e.class} - #{e.message}")
+    { status: :error, message: "Error connecting to SMTP server: #{e.message}" }
+  end
+
+  def debug_print(message)
+    puts message if @debug
+  end
+end
diff --git a/app/lib/smtp_validator.rb b/app/lib/smtp_validator.rb
deleted file mode 100644
index 032cdb2393..0000000000
--- a/app/lib/smtp_validator.rb
+++ /dev/null
@@ -1,60 +0,0 @@
-require 'net/smtp'
-require 'openssl'
-
-class SMTPValidator
-  def self.validate(email, options = {})
-    domain = email.split('@').last
-    smtp_server = options[:smtp_server] || domain
-    smtp_port = options[:smtp_port] || 587
-    helo_domain = options[:helo_domain] || 'localhost'
-    user_name = options[:user_name]
-    password = options[:password]
-    from_address = options[:from_address] || user_name
-    auth_methods = options[:auth_methods] || [:plain, :login, :cram_md5]
-    
-    result = { valid: false, code: nil, message: nil, auth_method: nil }
-    
-    begin
-      smtp = Net::SMTP.new(smtp_server, smtp_port)
-      smtp.enable_starttls_auto
-      smtp.open_timeout = 5
-      smtp.read_timeout = 5
-      
-      auth_methods.each do |method|
-        begin
-          smtp.start(helo_domain, user_name, password, method) do |smtp|
-            from_response = smtp.mailfrom(from_address)
-            result[:code], result[:message] = from_response.string.split(' ', 2)
-            
-            to_response = smtp.rcptto(email)
-            result[:code], result[:message] = to_response.string.split(' ', 2)
-            result[:valid] = result[:code].to_i == 250
-          end
-          result[:auth_method] = method
-          break
-        rescue Net::SMTPAuthenticationError => e
-          puts "Authentication failed with method #{method}: #{e.message}"
-          result[:code], result[:message] = e.message.split(' ', 2)
-          next
-        rescue Net::SMTPFatalError => e
-          result[:code], result[:message] = e.message.split(' ', 2)
-          break
-        end
-      end
-    rescue => e
-      puts "Connection Error: #{e.message}"
-      result[:message] = e.message
-    ensure
-      smtp.finish if smtp && smtp.started?
-    end
-    
-    if result[:auth_method]
-      puts "Email #{email} validation completed (authenticated with #{result[:auth_method]})"
-    else
-      puts "Failed to authenticate with any method"
-    end
-    
-    puts "Valid: #{result[:valid]}, Code: #{result[:code]}, Message: #{result[:message]}"
-    result
-  end
-end