added smtp validator

Gemfile.lock

@@ -293,7 +293,7 @@ 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)
@@ -606,4 +606,4 @@ DEPENDENCIES
   wkhtmltopdf-binary (~> 0.12.6.1)
 
 BUNDLED WITH
-   2.5.4
+   2.5.15

app/lib/smtp_validator.rb

@@ -0,0 +1,60 @@
+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