diff --git a/app/models/channel/filter/identify_sender.rb b/app/models/channel/filter/identify_sender.rb
index 7818f251f..9b271c556 100644
--- a/app/models/channel/filter/identify_sender.rb
+++ b/app/models/channel/filter/identify_sender.rb
@@ -95,16 +95,19 @@ module Channel::Filter::IdentifySender
     max_count = 40
     current_count = 0
     ['raw-to', 'raw-cc'].each do |item|
-      next if !mail[item.to_sym]
+      next if mail[item.to_sym].blank?
       begin
-        next if !mail[item.to_sym].addrs
         items = mail[item.to_sym].addrs
+        next if items.blank?
         items.each do |address_data|
-          next if address_data.address.blank?
+          email_address = address_data.address
+          next if email_address.blank?
+          next if email_address !~ /@/
+          next if email_address.match?(/\s/)
           user_create(
             firstname: address_data.display_name,
             lastname: '',
-            email: address_data.address,
+            email: email_address,
           )
           current_count += 1
           return false if current_count == max_count
@@ -126,6 +129,8 @@ module Channel::Filter::IdentifySender
             display_name = $1
           end
           next if address.blank?
+          next if address !~ /@/
+          next if address.match?(/\s/)
           user_create(
             firstname: display_name,
             lastname: '',
@@ -176,7 +181,7 @@ module Channel::Filter::IdentifySender
     data[:updated_by_id] = 1
     data[:created_by_id] = 1
 
-    user = User.create(data)
+    user = User.create!(data)
     user.update!(
       updated_by_id: user.id,
       created_by_id: user.id,
diff --git a/test/unit/email_process_test.rb b/test/unit/email_process_test.rb
index b945e0737..a16cbd090 100644
--- a/test/unit/email_process_test.rb
+++ b/test/unit/email_process_test.rb
@@ -203,6 +203,74 @@ Some Text",
           ],
         },
       },
+      {
+        data: "From: sender@example.com
+To: some_new_customer423@example.com
+Cc: some recipient <some with invalid@example.com>, max <somebody_else@example.com>
+Subject: abc some subject2
+
+Some Text",
+        success: true,
+        result: {
+          0 => {
+            priority: '2 normal',
+            title: 'abc some subject2',
+          },
+          1 => {
+            body: 'Some Text',
+            sender: 'Customer',
+            type: 'email',
+            internal: false,
+          },
+        },
+        verify: {
+          users: [
+            {
+              firstname: 'max',
+              lastname: '',
+              fullname: 'max',
+              email: 'somebody_else@example.com',
+            },
+            {
+              firstname: '',
+              lastname: '',
+              fullname: 'some_new_customer423@example.com',
+              email: 'some_new_customer423@example.com',
+            },
+          ],
+        },
+      },
+      {
+        data: "From: sender@example.com
+To: some_new_customer424@example.com
+Subject: abc some subject3
+Reply-To: some user <no-reply-with invalid-spaces@example.com>
+
+Some Text",
+        success: true,
+        result: {
+          0 => {
+            priority: '2 normal',
+            title: 'abc some subject3',
+          },
+          1 => {
+            body: 'Some Text',
+            sender: 'Customer',
+            type: 'email',
+            internal: false,
+          },
+        },
+        verify: {
+          users: [
+            {
+              firstname: '',
+              lastname: '',
+              fullname: 'some_new_customer424@example.com',
+              email: 'some_new_customer424@example.com',
+            },
+          ],
+        },
+      },
       {
         data: "From: me@example.com
 To: Alexander Ha <service-d1@example.com>,
@@ -2812,9 +2880,9 @@ Some Text',
             # verify if users are created
             if file[:verify][:users]
               file[:verify][:users].each { |user_result|
-                user = User.where(email: user_result[:email]).first
+                user = User.where(email: user_result[:email].downcase).first
                 if !user
-                  assert(false, "No user '#{user_result[:email]}' found!")
+                  assert(false, "No user '#{user_result[:email].downcase}' found!")
                   return
                 end
                 user_result.each { |key, value|