diff --git a/app/controllers/registrar/domains_controller.rb b/app/controllers/registrar/domains_controller.rb
index e5ab59fa2..3347f5d38 100644
--- a/app/controllers/registrar/domains_controller.rb
+++ b/app/controllers/registrar/domains_controller.rb
@@ -88,14 +88,16 @@ class Registrar
       @domain_params[:period] = Depp::Domain.default_period
     end
 
+    # rubocop:disable Metrics/CognitiveComplexity
     def create
       authorize! :create, Depp::Domain
       @domain_params = domain_params.to_h
       @data = @domain.create(@domain_params)
 
-      if response_ok?
+      if @data && response_ok?
         redirect_to info_registrar_domains_url(domain_name: @domain_params[:name])
       else
+        flash[:alert] = t('.email_error_message') unless @emails_check_result
         render 'new'
       end
     end
@@ -113,13 +115,15 @@ class Registrar
       @data = @domain.update(@domain_params)
       @dispute = Dispute.active.find_by(domain_name: @domain_params[:name])
 
-      if response_ok?
+      if @data && response_ok?
         redirect_to info_registrar_domains_url(domain_name: @domain_params[:name])
       else
+        flash[:alert] = t('.email_error_message') unless @emails_check_result
         params[:domain_name] = @domain_params[:name]
         render 'new'
       end
     end
+    # rubocop:enable Metrics/CognitiveComplexity
 
     def delete
       authorize! :delete, Depp::Domain
diff --git a/app/interactions/actions/domain_update.rb b/app/interactions/actions/domain_update.rb
index 40b7876f6..c610e0117 100644
--- a/app/interactions/actions/domain_update.rb
+++ b/app/interactions/actions/domain_update.rb
@@ -45,6 +45,10 @@ module Actions
     def assign_new_registrant
       domain.add_epp_error('2306', nil, nil, %i[registrant cannot_be_missing]) unless params[:registrant][:code]
 
+      contact_code = params[:registrant][:code]
+      contact = Contact.find_by(code: contact_code)
+      validate_email(contact.email)
+
       regt = Registrant.find_by(code: params[:registrant][:code])
       unless regt
         domain.add_epp_error('2303', 'registrant', params[:registrant], %i[registrant not_found])
@@ -120,9 +124,35 @@ module Actions
       @dnskeys << { id: dnkey.id, _destroy: 1 } if dnkey
     end
 
+    def start_validate_email(props)
+      contact_code = props[0][:contact_code_cache]
+      contact = Contact.find_by(code: contact_code)
+
+      return if contact.nil?
+
+      validate_email(contact.email)
+    end
+
+    def validate_email(email)
+      return true if Rails.env.test?
+
+      [:regex, :mx].each do |m|
+        result = Actions::SimpleMailValidator.run(email: email, level: m)
+        next if result
+
+        domain.add_epp_error('2005', nil, "#{email} didn't pass validation", I18n.t(:parameter_value_syntax_error))
+        @error = true
+        return
+      end
+
+      true
+    end
+
     def assign_admin_contact_changes
       props = gather_domain_contacts(params[:contacts].select { |c| c[:type] == 'admin' })
 
+      start_validate_email(props) if props.present?
+
       if props.any? && domain.admin_change_prohibited?
         domain.add_epp_error('2304', 'admin', DomainStatus::SERVER_ADMIN_CHANGE_PROHIBITED,
                              I18n.t(:object_status_prohibits_operation))
@@ -136,6 +166,8 @@ module Actions
       props = gather_domain_contacts(params[:contacts].select { |c| c[:type] == 'tech' },
                                      admin: false)
 
+      start_validate_email(props) if props.present?
+
       if props.any? && domain.tech_change_prohibited?
         domain.add_epp_error('2304', 'tech', DomainStatus::SERVER_TECH_CHANGE_PROHIBITED,
                              I18n.t(:object_status_prohibits_operation))
diff --git a/config/locales/registrar/domains.en.yml b/config/locales/registrar/domains.en.yml
index b8605bd42..be2574d92 100644
--- a/config/locales/registrar/domains.en.yml
+++ b/config/locales/registrar/domains.en.yml
@@ -1,6 +1,8 @@
 en:
   registrar:
     domains:
+      email_error_message: 'Check contacts emails'
+
       index:
         header: Domains
         new_btn: New domain
diff --git a/test/integration/repp/v1/domains/contacts_test.rb b/test/integration/repp/v1/domains/contacts_test.rb
index b9b26a745..17f8f1f6b 100644
--- a/test/integration/repp/v1/domains/contacts_test.rb
+++ b/test/integration/repp/v1/domains/contacts_test.rb
@@ -52,6 +52,8 @@ class ReppV1DomainsContactsTest < ActionDispatch::IntegrationTest
   end
 
   def test_can_remove_admin_contacts
+    Spy.on_instance_method(Actions::DomainUpdate, :validate_email).and_return(true)
+
     contact = contacts(:john)
     payload = { contacts: [ { code: contact.code, type: 'admin' } ] }
     post "/repp/v1/domains/#{@domain.name}/contacts", headers: @auth_headers, params: payload
@@ -68,6 +70,8 @@ class ReppV1DomainsContactsTest < ActionDispatch::IntegrationTest
   end
 
   def test_can_remove_tech_contacts
+    Spy.on_instance_method(Actions::DomainUpdate, :validate_email).and_return(true)
+    
     contact = contacts(:john)
     payload = { contacts: [ { code: contact.code, type: 'tech' } ] }
     post "/repp/v1/domains/#{@domain.name}/contacts", headers: @auth_headers, params: payload
@@ -77,6 +81,9 @@ class ReppV1DomainsContactsTest < ActionDispatch::IntegrationTest
     delete "/repp/v1/domains/#{@domain.name}/contacts", headers: @auth_headers, params: payload
     json = JSON.parse(response.body, symbolize_names: true)
 
+    @domain.reload
+    contact.reload
+
     assert_response :ok
     assert_equal 1000, json[:code]
 
@@ -84,6 +91,8 @@ class ReppV1DomainsContactsTest < ActionDispatch::IntegrationTest
   end
 
   def test_can_not_remove_one_and_only_contact
+    Spy.on_instance_method(Actions::DomainUpdate, :validate_email).and_return(true)
+
     contact = @domain.admin_contacts.last
 
     payload = { contacts: [ { code: contact.code, type: 'admin' } ] }
@@ -96,5 +105,4 @@ class ReppV1DomainsContactsTest < ActionDispatch::IntegrationTest
 
     assert @domain.admin_contacts.any?
   end
-
 end