diff --git a/app/mailers/mailer_ability.rb b/app/mailers/mailer_ability.rb
index 5cd5574cd9..50d9a869a1 100644
--- a/app/mailers/mailer_ability.rb
+++ b/app/mailers/mailer_ability.rb
@@ -11,5 +11,15 @@ def initialize(user, **params)
     @params = params
 
     can :receive, :all
+
+    cannot :receive, 'request_mailer#old_unclassified_updated' do
+      info_request.created_at <= 6.months.ago
+    end
+  end
+
+  private
+
+  def info_request
+    params[:info_request]
   end
 end
diff --git a/doc/CHANGES.md b/doc/CHANGES.md
index eff6059035..e320c693d2 100644
--- a/doc/CHANGES.md
+++ b/doc/CHANGES.md
@@ -2,7 +2,9 @@
 
 ## Highlighted Features
 
-Add additional InfoRequest embargo scopes (Graeme Porteous)
+* Prevent request classification notifications from being set if request is
+  older than 6 months (Graeme Porteous)
+* Add additional InfoRequest embargo scopes (Graeme Porteous)
 
 # 0.45.3.1
 
diff --git a/spec/mailers/mailer_ability_spec.rb b/spec/mailers/mailer_ability_spec.rb
index b21abc0195..849879ab67 100644
--- a/spec/mailers/mailer_ability_spec.rb
+++ b/spec/mailers/mailer_ability_spec.rb
@@ -87,7 +87,17 @@
 
   describe 'RequestMailer#old_unclassified_updated' do
     let(:name) { 'request_mailer#old_unclassified_updated' }
-    it { expect(ability).to be_able_to(:receive, name) }
+    let(:ability) { MailerAbility.new(user, info_request: info_request) }
+
+    context 'when info request when sent less than 6 months ago' do
+      let(:info_request) { double(:InfoRequest, created_at: 6.months.ago + 1) }
+      it { expect(ability).to be_able_to(:receive, name) }
+    end
+
+    context 'when info request when sent more than 6 months ago' do
+      let(:info_request) { double(:InfoRequest, created_at: 6.months.ago) }
+      it { expect(ability).not_to be_able_to(:receive, name) }
+    end
   end
 
   describe 'RequestMailer#not_clarified_alert' do
diff --git a/spec/mailers/previews/request_mailer_preview.rb b/spec/mailers/previews/request_mailer_preview.rb
index 54e96318e5..5346d24e7b 100644
--- a/spec/mailers/previews/request_mailer_preview.rb
+++ b/spec/mailers/previews/request_mailer_preview.rb
@@ -43,7 +43,8 @@ def info_request
       url_title: 'a_request',
       user: User.first,
       public_body: PublicBody.first,
-      described_state: 'successful'
+      described_state: 'successful',
+      created_at: Time.now
     )
   end
 
diff --git a/spec/mailers/request_mailer_spec.rb b/spec/mailers/request_mailer_spec.rb
index 0de4bd9b33..c2c953690c 100644
--- a/spec/mailers/request_mailer_spec.rb
+++ b/spec/mailers/request_mailer_spec.rb
@@ -542,6 +542,11 @@ def sent_alert_params(request, type)
       expect(mail.subject).to eq('Someone has updated the status of your request')
     end
 
+    it 'delivers the email' do
+      mail.deliver_now
+      expect(ActionMailer::Base.deliveries).to_not be_empty
+    end
+
     context "when the user does not use default locale" do
       before do
         info_request.user.locale = 'es'
@@ -554,6 +559,21 @@ def sent_alert_params(request, type)
       end
     end
 
+    context 'when the info request was created over 6 months ago' do
+      let(:info_request) do
+        FactoryBot.create(
+          :info_request,
+          user: user, title: "Test request", public_body: public_body,
+          url_title: "test_request", created_at: 6.months.ago
+        )
+      end
+
+      it 'does not deliver the email' do
+        mail.deliver_now
+        expect(ActionMailer::Base.deliveries).to be_empty
+      end
+    end
+
     it 'should tell them what status was picked' do
       expect(mail.body).to match(/"refused."/)
     end