diff --git a/app/controllers/new_gestionnaire/avis_controller.rb b/app/controllers/new_gestionnaire/avis_controller.rb
index e8267f944..7cb207e7a 100644
--- a/app/controllers/new_gestionnaire/avis_controller.rb
+++ b/app/controllers/new_gestionnaire/avis_controller.rb
@@ -50,7 +50,7 @@ module NewGestionnaire
     end
 
     def create_commentaire
-      @commentaire = Commentaire.new(commentaire_params.merge(email: current_gestionnaire.email, dossier: avis.dossier))
+      @commentaire = CommentaireService.build(current_gestionnaire, avis.dossier, commentaire_params)
 
       if @commentaire.save
         flash.notice = "Message envoyé"
diff --git a/app/controllers/new_gestionnaire/dossiers_controller.rb b/app/controllers/new_gestionnaire/dossiers_controller.rb
index 473d66d08..2ae4e52da 100644
--- a/app/controllers/new_gestionnaire/dossiers_controller.rb
+++ b/app/controllers/new_gestionnaire/dossiers_controller.rb
@@ -106,7 +106,7 @@ module NewGestionnaire
     end
 
     def create_commentaire
-      @commentaire = CommentaireService.create(current_gestionnaire, dossier, commentaire_params)
+      @commentaire = CommentaireService.build(current_gestionnaire, dossier, commentaire_params)
 
       if @commentaire.save
         current_gestionnaire.follow(dossier)
diff --git a/app/controllers/new_user/dossiers_controller.rb b/app/controllers/new_user/dossiers_controller.rb
index 57e8e6117..9faa079a4 100644
--- a/app/controllers/new_user/dossiers_controller.rb
+++ b/app/controllers/new_user/dossiers_controller.rb
@@ -172,7 +172,7 @@ module NewUser
     end
 
     def create_commentaire
-      @commentaire = CommentaireService.create(current_user, dossier, commentaire_params)
+      @commentaire = CommentaireService.build(current_user, dossier, commentaire_params)
 
       if @commentaire.save
         flash.notice = "Votre message a bien été envoyé à l’instructeur en charge de votre dossier."
diff --git a/app/controllers/support_controller.rb b/app/controllers/support_controller.rb
index 45f4c074d..330100091 100644
--- a/app/controllers/support_controller.rb
+++ b/app/controllers/support_controller.rb
@@ -62,11 +62,12 @@ class SupportController < ApplicationController
   end
 
   def create_commentaire
-    dossier.commentaires.create(
-      email: email,
+    params = {
       file: params[:file],
       body: "[#{params[:subject]}]<br><br>#{params[:text]}"
-    )
+    }
+    commentaire = CommentaireService.build_with_email(email, dossier, params)
+    commentaire.save!
   end
 
   def tags
diff --git a/app/mailers/notification_mailer.rb b/app/mailers/notification_mailer.rb
index 503bd4bf0..8b855662d 100644
--- a/app/mailers/notification_mailer.rb
+++ b/app/mailers/notification_mailer.rb
@@ -46,10 +46,8 @@ class NotificationMailer < ApplicationMailer
   end
 
   def create_commentaire_for_notification(dossier, subject, body)
-    Commentaire.create(
-      dossier: dossier,
-      email: CONTACT_EMAIL,
-      body: ["[#{subject}]", body].join("<br><br>")
-    )
+    params = { body: ["[#{subject}]", body].join("<br><br>") }
+    commentaire = CommentaireService.build_with_email(CONTACT_EMAIL, dossier, params)
+    commentaire.save!
   end
 end
diff --git a/app/models/commentaire.rb b/app/models/commentaire.rb
index cfe068626..5a49b6e84 100644
--- a/app/models/commentaire.rb
+++ b/app/models/commentaire.rb
@@ -2,6 +2,9 @@ class Commentaire < ApplicationRecord
   belongs_to :dossier, touch: true
   belongs_to :piece_justificative
 
+  belongs_to :user
+  belongs_to :gestionnaire
+
   mount_uploader :file, CommentaireFileUploader
   validates :file, file_size: { maximum: 20.megabytes, message: "La taille du fichier doit être inférieure à 20 Mo" }
   validate :is_virus_free?
@@ -16,6 +19,16 @@ class Commentaire < ApplicationRecord
     super.reject { |c| c.name == "champ" }
   end
 
+  def email
+    if user
+      user.email
+    elsif gestionnaire
+      gestionnaire.email
+    else
+      read_attribute(:email)
+    end
+  end
+
   def header
     "#{sender}, #{I18n.l(created_at, format: '%d %b %Y %H:%M')}"
   end
diff --git a/app/services/commentaire_service.rb b/app/services/commentaire_service.rb
index c70ddf815..fa3b9a576 100644
--- a/app/services/commentaire_service.rb
+++ b/app/services/commentaire_service.rb
@@ -1,16 +1,18 @@
 class CommentaireService
   class << self
-    def create(sender, dossier, params)
-      attributes = params.merge(email: sender.email, dossier: dossier)
-
-      # If the user submits a empty message, simple_format will replace '' by '<p></p>',
-      # and thus bypass the not-empty constraint on commentaire's body.
-      #
-      # To avoid this, format the message only if a body is present in the first place.
-      if attributes[:body].present?
-        attributes[:body] = ActionController::Base.helpers.simple_format(attributes[:body])
+    def build(sender, dossier, params)
+      case sender
+      when User
+        params[:user] = sender
+      when Gestionnaire
+        params[:gestionnaire] = sender
       end
 
+      build_with_email(sender.email, dossier, params)
+    end
+
+    def build_with_email(email, dossier, params)
+      attributes = params.merge(email: email, dossier: dossier)
       Commentaire.new(attributes)
     end
   end
diff --git a/app/views/shared/dossiers/messages/_message.html.haml b/app/views/shared/dossiers/messages/_message.html.haml
index a1b78bc9d..39ac76ef3 100644
--- a/app/views/shared/dossiers/messages/_message.html.haml
+++ b/app/views/shared/dossiers/messages/_message.html.haml
@@ -8,7 +8,7 @@
       %span.guest Invité
     %span.date{ class: highlight_if_unseen_class(messagerie_seen_at, commentaire.created_at) }
       = commentaire_date(commentaire)
-  .rich-text= sanitize(commentaire.body)
+  .rich-text= sanitize(simple_format(commentaire.body))
 
   - if commentaire.piece_justificative
     .attachment-link
diff --git a/spec/controllers/new_gestionnaire/dossiers_controller_spec.rb b/spec/controllers/new_gestionnaire/dossiers_controller_spec.rb
index ac3dc3361..6ebdc7a0e 100644
--- a/spec/controllers/new_gestionnaire/dossiers_controller_spec.rb
+++ b/spec/controllers/new_gestionnaire/dossiers_controller_spec.rb
@@ -301,7 +301,7 @@ describe NewGestionnaire::DossiersController, type: :controller do
 
         expect(response).to render_template :messagerie
         expect(flash.alert).to be_present
-        expect(assigns(:commentaire).body).to eq("<p>avant\n<br />apres</p>")
+        expect(assigns(:commentaire).body).to eq("avant\napres")
       end
     end
   end
diff --git a/spec/controllers/new_user/dossiers_controller_spec.rb b/spec/controllers/new_user/dossiers_controller_spec.rb
index 6bc393ea2..27726b35f 100644
--- a/spec/controllers/new_user/dossiers_controller_spec.rb
+++ b/spec/controllers/new_user/dossiers_controller_spec.rb
@@ -787,7 +787,7 @@ describe NewUser::DossiersController, type: :controller do
 
         expect(response).to render_template :messagerie
         expect(flash.alert).to be_present
-        expect(assigns(:commentaire).body).to eq("<p>avant\n<br />apres</p>")
+        expect(assigns(:commentaire).body).to eq("avant\napres")
       end
     end
   end
diff --git a/spec/services/commentaire_service_spec.rb b/spec/services/commentaire_service_spec.rb
index 55e5f3115..d781ca8ca 100644
--- a/spec/services/commentaire_service_spec.rb
+++ b/spec/services/commentaire_service_spec.rb
@@ -8,7 +8,7 @@ describe CommentaireService do
     let(:file) { nil }
     let(:scan_result) { true }
 
-    subject(:commentaire) { CommentaireService.create(sender, dossier, { body: body, file: file }) }
+    subject(:commentaire) { CommentaireService.build(sender, dossier, { body: body, file: file }) }
 
     before do
       allow(ClamavService).to receive(:safe_file?).and_return(scan_result)
@@ -17,7 +17,7 @@ describe CommentaireService do
     it 'creates a new valid commentaire' do
       expect(commentaire.email).to eq sender.email
       expect(commentaire.dossier).to eq dossier
-      expect(commentaire.body).to eq '<p>Contenu du message.</p>'
+      expect(commentaire.body).to eq 'Contenu du message.'
       expect(commentaire.file).to be_blank
       expect(commentaire).to be_valid
     end