diff --git a/app/controllers/backoffice/avis_controller.rb b/app/controllers/backoffice/avis_controller.rb
index 5817e0c81..3ed67fa9e 100644
--- a/app/controllers/backoffice/avis_controller.rb
+++ b/app/controllers/backoffice/avis_controller.rb
@@ -7,7 +7,7 @@ class Backoffice::AvisController < ApplicationController
     avis = Avis.new(create_params.merge(claimant: current_gestionnaire, dossier: dossier))
 
     if avis.save
-      flash[:notice] = "Votre demande d'avis a bien été envoyée à #{create_params[:email]}"
+      flash[:notice] = "Votre demande d'avis a bien été envoyée à #{avis.email}"
     end
 
     redirect_to backoffice_dossier_path(dossier)
diff --git a/app/models/avis.rb b/app/models/avis.rb
index 89e29c5a3..9d2253a2f 100644
--- a/app/models/avis.rb
+++ b/app/models/avis.rb
@@ -3,6 +3,7 @@ class Avis < ApplicationRecord
   belongs_to :gestionnaire
   belongs_to :claimant, class_name: 'Gestionnaire'
 
+  before_save :downcase_email
   before_create :try_to_assign_gestionnaire
   after_create :notify_gestionnaire
 
@@ -27,6 +28,12 @@ class Avis < ApplicationRecord
 
   private
 
+  def downcase_email
+    if email.present?
+      email.downcase!
+    end
+  end
+
   def notify_gestionnaire
     AvisMailer.avis_invitation(self).deliver_now
   end
diff --git a/spec/models/avis_spec.rb b/spec/models/avis_spec.rb
index cb8de8cce..0dd7ef2ac 100644
--- a/spec/models/avis_spec.rb
+++ b/spec/models/avis_spec.rb
@@ -117,4 +117,26 @@ RSpec.describe Avis, type: :model do
       it { expect(avis.email).to eq(email) }
     end
   end
+
+  describe "#downcase_email" do
+    subject { Avis.create(claimant: claimant, email: email, dossier: create(:dossier), gestionnaire: create(:gestionnaire)) }
+
+    context "when there is no email" do
+      let(:email) { nil }
+
+      it { expect(subject.email).to be_nil }
+    end
+
+    context "when the email is in lowercase" do
+      let(:email) { "toto@tps.fr" }
+
+      it { expect(subject.email).to eq("toto@tps.fr") }
+    end
+
+    context "when the email is not in lowercase" do
+      let(:email) { "TOTO@tps.fr" }
+
+      it { expect(subject.email).to eq("toto@tps.fr") }
+    end
+  end
 end