diff --git a/lib/sisimai/rhost.rb b/lib/sisimai/rhost.rb
index 1130a198..829438c6 100644
--- a/lib/sisimai/rhost.rb
+++ b/lib/sisimai/rhost.rb
@@ -25,18 +25,16 @@ class << self
         "YahooInc"    => [".yahoodns.net"],
       }.freeze
 
-      # Detect the bounce reason from certain remote hosts
+      # Returns the rhost class name
       # @param    [Hash]   argvs  Decoded email data
-      # @return   [String]        The value of bounce reason
-      def find(argvs)
-        return "" if argvs["diagnosticcode"].empty?
+      # @return   [String]        rhost class name
+      def name(argvs)
+        return "" if argvs.nil?
 
+        rhostclass = ""
         clienthost = argvs["lhost"].downcase
         remotehost = argvs["rhost"].downcase
         domainpart = argvs["destination"].downcase
-        rhostclass = ""
-        modulename = ""
-        return "" if (remotehost + domainpart).empty?
 
         catch :FINDRHOST do
           # Try to match the hostname patterns with the following order:
@@ -46,14 +44,14 @@ def find(argvs)
           RhostClass.each_key do |e|
             # Try to match the domain part of the recipient address with each value of RhostClass
             next unless RhostClass[e].any? { |a| a.end_with?(domainpart) }
-            modulename = 'Sisimai::Rhost::' << e
+            rhostclass = e
             throw :FINDRHOST
           end
 
           RhostClass.each_key do |e|
             # Try to match the remote host with each value of RhostClass
             next unless RhostClass[e].any? { |a| remotehost.end_with?(a) }
-            modulename = 'Sisimai::Rhost::' << e
+            rhostclass = e
             throw :FINDRHOST
           end
 
@@ -61,13 +59,24 @@ def find(argvs)
           RhostClass.each_key do |e|
             # Try to match the client host with each value of RhostClass
             next unless RhostClass[e].any? { |a| clienthost.end_with?(a) }
-            modulename = 'Sisimai::Rhost::' << e
+            rhostclass = e
             throw :FINDRHOST
           end
         end
-        return "" if modulename.empty?
+        return rhostclass
+      end
+
+      # Detect the bounce reason from certain remote hosts
+      # @param    [Hash]   argvs  Decoded email data
+      # @return   [String]        The value of bounce reason
+      def find(argvs)
+        return "" if argvs.nil?
+
+        rhostclass = name(argvs); return "" if rhostclass.empty?
+        modulepath = "sisimai/rhost/"   << rhostclass.downcase; require modulepath
+        modulename = "Sisimai::Rhost::" << rhostclass
 
-        rhostclass = "sisimai/rhost/" << modulename.downcase.split("::")[2]; require rhostclass
+        #rhostclass = "sisimai/rhost/" << modulename.downcase.split("::")[2]; require rhostclass
         reasontext = Module.const_get(modulename).find(argvs)
         return "" if reasontext.empty?
         return reasontext
diff --git a/test/public/mail-maildir-test.rb b/test/public/mail-maildir-test.rb
index e52ec513..e6a3d7d2 100644
--- a/test/public/mail-maildir-test.rb
+++ b/test/public/mail-maildir-test.rb
@@ -5,7 +5,7 @@ class MailMaildirTest < Minitest::Test
   Methods = { class: %w[new], object: %w[path dir file size handle offset read] }
   Samples = ['./set-of-emails/maildir/bsd', './set-of-emails/maildir/mac']
   Maildir = Sisimai::Mail::Maildir.new(Samples[0])
-  DirSize = 585
+  DirSize = 599
 
   def test_methods
     Methods[:class].each  { |e| assert_respond_to Sisimai::Mail::Maildir, e }
diff --git a/test/public/rhost-test.rb b/test/public/rhost-test.rb
index e43dabc5..a83bf150 100644
--- a/test/public/rhost-test.rb
+++ b/test/public/rhost-test.rb
@@ -3,35 +3,43 @@
 require 'sisimai'
 
 class RhostTest < Minitest::Test
-  Methods = { class:  %w[find] }
+  Methods = { class:  %w[name find] }
+  Classes = %w[
+    Aol Apple Cox Facebook FrancePTT GoDaddy Google GSuite IUA KDDI MessageLabs Microsoft Mimecast
+    NTTDOCOMO Outlook Spectrum Tencent YahooInc
+  ]
+  Objects = []
 
   def test_methods
     Methods[:class].each { |e| assert_respond_to Sisimai::Rhost, e }
   end
 
-  def test_find
+  def test_name
     Dir.glob('./set-of-emails/maildir/bsd/rhost-*.eml').each do |e|
-      cv = Sisimai.rise(e)
-      assert_instance_of Array, cv
-
+      cv = Sisimai.rise(e); assert_instance_of Array, cv
+      warn "\nFile = " << e
       cv.each do |ee|
         assert_instance_of Sisimai::Fact, ee
-        assert_instance_of String, ee.rhost
-        assert_instance_of String, ee.reason
-        refute_empty ee.rhost
-        refute_empty ee.reason
-        cx = ee.damn
-
-        cr = Sisimai::Rhost.find(cx)
-        refute_empty cx['destination']
-        refute_empty cx['reason']
+        fo = ee.damn
+        cx = Sisimai::Rhost.name(fo); refute_empty cx
+        Objects << fo
       end
-
     end
 
     ce = assert_raises ArgumentError do
-      Sisimai::Rhost.find()
-      Sisimai::Rhost.find(nil, nil, nil)
+      Sisimai::Rhost.name()
+      Sisimai::Rhost.name(nil, nil)
+    end
+  end
+
+  def test_find
+    Objects.each do |fo|
+      cr = Sisimai::Rhost.find(fo); assert_instance_of ::String, cr
+
+      ce = assert_raises ArgumentError do
+        Sisimai::Rhost.find()
+        Sisimai::Rhost.find(nil,  nil)
+      end
     end
   end
 end