diff --git a/app/controllers/manager/procedures_controller.rb b/app/controllers/manager/procedures_controller.rb
index dd0dcf0f1..9ca75b503 100644
--- a/app/controllers/manager/procedures_controller.rb
+++ b/app/controllers/manager/procedures_controller.rb
@@ -41,7 +41,7 @@ module Manager
 
     def export_mail_brouillons
       dossiers = procedure.dossiers.state_brouillon.includes(:user)
-      emails = dossiers.map { |d| d.user.email }.sort.uniq
+      emails = dossiers.map { |dossier| dossier.user_email_for(:display) }.sort.uniq
       date = Time.zone.now.strftime('%d-%m-%Y')
       send_data(emails.join("\n"), :filename => "brouillons-#{procedure.id}-au-#{date}.csv")
     end
diff --git a/app/graphql/types/dossier_type.rb b/app/graphql/types/dossier_type.rb
index 7f340ffc3..57811a75e 100644
--- a/app/graphql/types/dossier_type.rb
+++ b/app/graphql/types/dossier_type.rb
@@ -54,7 +54,11 @@ module Types
     end
 
     def usager
-      Loaders::Record.for(User).load(object.user_id)
+      if object.user_deleted?
+        { email: object.user_email_for(:display), id: -1 }
+      else
+        Loaders::Record.for(User).load(object.user_id)
+      end
     end
 
     def groupe_instructeur
diff --git a/app/mailers/dossier_mailer.rb b/app/mailers/dossier_mailer.rb
index 285802797..29e035ffc 100644
--- a/app/mailers/dossier_mailer.rb
+++ b/app/mailers/dossier_mailer.rb
@@ -13,7 +13,7 @@ class DossierMailer < ApplicationMailer
 
     subject = "Retrouvez votre brouillon pour la démarche « #{dossier.procedure.libelle} »"
 
-    mail(from: NO_REPLY_EMAIL, to: dossier.user.email, subject: subject) do |format|
+    mail(from: NO_REPLY_EMAIL, to: dossier.user_email_for(:notification), subject: subject) do |format|
       format.html { render layout: 'mailers/notifications_layout' }
     end
   end
@@ -25,7 +25,7 @@ class DossierMailer < ApplicationMailer
 
     subject = "Nouveau message pour votre dossier nº #{dossier.id} (#{dossier.procedure.libelle})"
 
-    mail(from: NO_REPLY_EMAIL, to: dossier.user.email, subject: subject) do |format|
+    mail(from: NO_REPLY_EMAIL, to: dossier.user_email_for(:notification), subject: subject) do |format|
       format.html { render layout: 'mailers/notifications_layout' }
     end
   end
@@ -49,7 +49,7 @@ class DossierMailer < ApplicationMailer
 
     subject = "Votre dossier nº #{@dossier.id} est en train d'être réexaminé"
 
-    mail(from: NO_REPLY_EMAIL, to: dossier.user.email, subject: subject) do |format|
+    mail(from: NO_REPLY_EMAIL, to: dossier.user_email_for(:notification), subject: subject) do |format|
       format.html { render layout: 'mailers/notifications_layout' }
     end
   end
@@ -139,7 +139,7 @@ class DossierMailer < ApplicationMailer
     @subject = "Attention : votre dossier n'est pas déposé."
     @dossier = dossier
 
-    mail(to: dossier.user.email, subject: @subject)
+    mail(to: dossier.user_email_for(:notification), subject: @subject)
   end
 
   protected
diff --git a/app/mailers/notification_mailer.rb b/app/mailers/notification_mailer.rb
index 829c7ce47..d958d781b 100644
--- a/app/mailers/notification_mailer.rb
+++ b/app/mailers/notification_mailer.rb
@@ -8,6 +8,8 @@
 class NotificationMailer < ApplicationMailer
   include ActionView::Helpers::SanitizeHelper
 
+  before_action :prevent_delivery_to_deleted_users
+
   helper ServiceHelper
   helper MailerHelper
 
@@ -36,8 +38,12 @@ class NotificationMailer < ApplicationMailer
 
   private
 
+  def prevent_delivery_to_deleted_users
+    !@dossier.user_deleted?
+  end
+
   def send_notification(dossier, mail_template)
-    email = dossier.user.email
+    email = dossier.user_email_for(:notification)
 
     subject = mail_template.subject_for_dossier(dossier)
     body = mail_template.body_for_dossier(dossier)
diff --git a/app/models/dossier.rb b/app/models/dossier.rb
index f8023d563..53ec3ff38 100644
--- a/app/models/dossier.rb
+++ b/app/models/dossier.rb
@@ -8,6 +8,7 @@
 #  autorisation_donnees                               :boolean
 #  brouillon_close_to_expiration_notice_sent_at       :datetime
 #  conservation_extension                             :interval         default(0 seconds)
+#  deleted_user_email_never_send                      :string
 #  en_construction_at                                 :datetime
 #  en_construction_close_to_expiration_notice_sent_at :datetime
 #  en_construction_conservation_extension             :interval         default(0 seconds)
@@ -137,9 +138,9 @@ class Dossier < ApplicationRecord
     end
 
     event :repasser_en_instruction, after: :after_repasser_en_instruction do
-      transitions from: :refuse, to: :en_instruction
-      transitions from: :sans_suite, to: :en_instruction
-      transitions from: :accepte, to: :en_instruction
+      transitions from: :refuse, to: :en_instruction, guard: :can_repasser_en_instruction?
+      transitions from: :sans_suite, to: :en_instruction, guard: :can_repasser_en_instruction?
+      transitions from: :accepte, to: :en_instruction, guard: :can_repasser_en_instruction?
     end
   end
 
@@ -249,6 +250,7 @@ class Dossier < ApplicationRecord
     states = opts[:notify_on_closed] ? [:publiee, :close, :depubliee] : [:publiee, :depubliee]
     joins(:procedure)
       .where(procedures: { aasm_state: states })
+      .where.not(user_id: nil)
   end
 
   scope :brouillon_close_to_expiration, -> do
@@ -350,6 +352,22 @@ class Dossier < ApplicationRecord
   validates :individual, presence: true, if: -> { revision.procedure.for_individual? }
   validates :groupe_instructeur, presence: true, if: -> { !brouillon? }
 
+  def user_deleted?
+    user_id.nil?
+  end
+
+  def user_email_for(use)
+    if user_deleted?
+      if use == :display
+        deleted_user_email_never_send
+      else
+        raise "Can not send email to discarded user"
+      end
+    else
+      user.email
+    end
+  end
+
   def motivation
     return nil if !termine?
     traitements.any? ? traitements.last.motivation : read_attribute(:motivation)
@@ -416,6 +434,10 @@ class Dossier < ApplicationRecord
     brouillon? && procedure.dossier_can_transition_to_en_construction?
   end
 
+  def can_repasser_en_instruction?
+    termine? && !user_deleted?
+  end
+
   def can_be_updated_by_user?
     brouillon? || en_construction?
   end
@@ -429,7 +451,7 @@ class Dossier < ApplicationRecord
   end
 
   def messagerie_available?
-    !brouillon? && !archived
+    !brouillon? && !user_deleted? && !archived
   end
 
   def en_construction_close_to_expiration?
@@ -590,13 +612,18 @@ class Dossier < ApplicationRecord
         administration_emails.each do |email|
           DossierMailer.notify_deletion_to_administration(deleted_dossier, email).deliver_later
         end
-        DossierMailer.notify_deletion_to_user(deleted_dossier, user.email).deliver_later
+
+        if !user_deleted?
+          DossierMailer.notify_deletion_to_user(deleted_dossier, user_email_for(:notification)).deliver_later
+        end
 
         log_dossier_operation(author, :supprimer, self)
       elsif termine?
         deleted_dossier = DeletedDossier.create_from_dossier(self, reason)
 
-        DossierMailer.notify_instructeur_deletion_to_user(deleted_dossier, user.email).deliver_later
+        if !user_deleted?
+          DossierMailer.notify_instructeur_deletion_to_user(deleted_dossier, user_email_for(:notification)).deliver_later
+        end
 
         log_dossier_operation(author, :supprimer, self)
       end
@@ -751,7 +778,7 @@ class Dossier < ApplicationRecord
   def spreadsheet_columns(with_etablissement: false, types_de_champ:, types_de_champ_private:)
     columns = [
       ['ID', id.to_s],
-      ['Email', user.email]
+      ['Email', user_email_for(:display)]
     ]
 
     if procedure.for_individual?
diff --git a/app/models/user.rb b/app/models/user.rb
index f9f6fa372..1e40adb85 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -170,18 +170,24 @@ class User < ApplicationRecord
   end
 
   def can_be_deleted?
-    !administrateur? && !instructeur? && !expert? && dossiers.with_discarded.state_instruction_commencee.empty?
+    !administrateur? && !instructeur? && !expert?
   end
 
   def delete_and_keep_track_dossiers(administration)
     if !can_be_deleted?
-      raise "Cannot delete this user because instruction has started for some dossiers"
+      raise "Cannot delete this user because they are also instructeur, expert or administrateur"
     end
 
-    dossiers.each do |dossier|
+    Invite.where(dossier: dossiers.with_discarded).destroy_all
+    dossiers.state_en_construction.each do |dossier|
       dossier.discard_and_keep_track!(administration, :user_removed)
     end
-    dossiers.with_discarded.destroy_all
+    DossierOperationLog
+      .where(dossier: dossiers.with_discarded.discarded)
+      .where.not(operation: DossierOperationLog.operations.fetch(:supprimer))
+      .destroy_all
+    dossiers.with_discarded.discarded.destroy_all
+    dossiers.update_all(deleted_user_email_never_send: email, user_id: nil)
     destroy!
   end
 
diff --git a/app/views/dossiers/show.pdf.prawn b/app/views/dossiers/show.pdf.prawn
index da28de24d..087502214 100644
--- a/app/views/dossiers/show.pdf.prawn
+++ b/app/views/dossiers/show.pdf.prawn
@@ -174,7 +174,7 @@ def add_message(pdf, message)
   if message.sent_by_system?
     sender = 'Email automatique'
   elsif message.sent_by?(@dossier.user)
-    sender = @dossier.user.email
+    sender = @dossier.user_email_for(:display)
   end
 
   format_in_2_lines(pdf, "#{sender}, #{try_format_date(message.created_at)}",
@@ -233,7 +233,7 @@ prawn_document(page_size: "A4") do |pdf|
     format_in_2_columns(pdf, 'Informations France Connect', "Le dossier a été déposé par le compte de #{@dossier.france_connect_information.given_name} #{@dossier.france_connect_information.family_name}, authentifié par France Connect le #{@dossier.france_connect_information.updated_at.strftime('%d/%m/%Y')}")
   end
 
-  format_in_2_columns(pdf, "Email", @dossier.user.email)
+  format_in_2_columns(pdf, "Email", @dossier.user_email_for(:display))
 
   if @dossier.individual.present?
     add_identite_individual(pdf, @dossier.individual)
diff --git a/app/views/experts/avis/procedure.html.haml b/app/views/experts/avis/procedure.html.haml
index fc79795d2..8abe0f3d4 100644
--- a/app/views/experts/avis/procedure.html.haml
+++ b/app/views/experts/avis/procedure.html.haml
@@ -38,7 +38,7 @@
               = link_to(instructeur_avis_path(avis.procedure, avis), class: 'cell-link') do
                 %span.icon.folder
                 #{avis.dossier.id}
-            %td= link_to(avis.dossier.user.email, instructeur_avis_path(avis.procedure, avis), class: 'cell-link')
+            %td= link_to(avis.dossier.user_email_for(:display), instructeur_avis_path(avis.procedure, avis), class: 'cell-link')
             %td= link_to(avis.procedure.libelle, instructeur_avis_path(avis.procedure, avis), class: 'cell-link')
     = paginate(@avis)
   - else
diff --git a/app/views/instructeurs/avis/procedure.html.haml b/app/views/instructeurs/avis/procedure.html.haml
index f38d6cde3..1505eef58 100644
--- a/app/views/instructeurs/avis/procedure.html.haml
+++ b/app/views/instructeurs/avis/procedure.html.haml
@@ -38,7 +38,7 @@
               = link_to(instructeur_avis_path(avis.procedure, avis), class: 'cell-link') do
                 %span.icon.folder
                 #{avis.dossier.id}
-            %td= link_to(avis.dossier.user.email, instructeur_avis_path(avis.procedure, avis), class: 'cell-link')
+            %td= link_to(avis.dossier.user_email_for(:display), instructeur_avis_path(avis.procedure, avis), class: 'cell-link')
             %td= link_to(avis.procedure.libelle, instructeur_avis_path(avis.procedure, avis), class: 'cell-link')
     = paginate(@avis)
   - else
diff --git a/app/views/instructeurs/dossiers/_state_button.html.haml b/app/views/instructeurs/dossiers/_state_button.html.haml
index 2b4d5851c..3d7b8e7bc 100644
--- a/app/views/instructeurs/dossiers/_state_button.html.haml
+++ b/app/views/instructeurs/dossiers/_state_button.html.haml
@@ -99,17 +99,24 @@
                 %h4 Voir l’attestation
                 %p Cette attestation a été envoyée automatiquement au demandeur.
 
-        %li
-          = link_to repasser_en_instruction_instructeur_dossier_path(dossier.procedure, dossier), method: :post, data: { remote:true, confirm: "Voulez vous remettre le dossier #{dossier.id} en instruction ?" } do
-            %span.icon.in-progress
-            .dropdown-description
-              %h4 Repasser en instruction
-              L’usager sera notifié que son dossier est réexaminé.
-        - if dossier.termine?
+        - if dossier.can_repasser_en_instruction?
           %li
-            = link_to supprimer_dossier_instructeur_dossier_path(dossier.procedure, dossier), method: :patch, data: { confirm: "Voulez vous vraiment supprimer le dossier #{dossier.id} ? Cette action est irréversible. \nNous vous suggérons de télécharger le dossier au format PDF au préalable." } do
-              %span.icon.delete
+            = link_to repasser_en_instruction_instructeur_dossier_path(dossier.procedure, dossier), method: :post, data: { remote:true, confirm: "Voulez vous remettre le dossier #{dossier.id} en instruction ?" } do
+              %span.icon.in-progress
               .dropdown-description
-                %h4 Supprimer le dossier
-                L’usager sera notifié que son dossier est supprimé.
+                %h4 Repasser en instruction
+                L’usager sera notifié que son dossier est réexaminé.
+        - elsif dossier.user_deleted?
+          %li
+            %span.icon.info
+            .dropdown-description
+              %h4 En attente d‘archivage
+              L'usager a supprimé son compte. Vous pouvez archiver puis supprimer le dossier.
+
+        %li
+          = link_to supprimer_dossier_instructeur_dossier_path(dossier.procedure, dossier), method: :patch, data: { confirm: "Voulez vous vraiment supprimer le dossier #{dossier.id} ? Cette action est irréversible. \nNous vous suggérons de télécharger le dossier au format PDF au préalable." } do
+            %span.icon.delete
+            .dropdown-description
+              %h4 Supprimer le dossier
+              L’usager sera notifié que son dossier est supprimé.
 
diff --git a/app/views/instructeurs/recherche/index.html.haml b/app/views/instructeurs/recherche/index.html.haml
index 7c7c3ce89..b08a849b5 100644
--- a/app/views/instructeurs/recherche/index.html.haml
+++ b/app/views/instructeurs/recherche/index.html.haml
@@ -27,7 +27,7 @@
               = link_to(dossier_linked_path(current_instructeur, dossier), class: 'cell-link') do
                 = dossier.id
             %td= link_to(dossier.procedure.libelle, dossier_linked_path(current_instructeur, dossier), class: 'cell-link')
-            %td= link_to(dossier.user.email, dossier_linked_path(current_instructeur, dossier), class: 'cell-link')
+            %td= link_to(dossier.user_email_for(:display), dossier_linked_path(current_instructeur, dossier), class: 'cell-link')
             %td.status-col
               = link_to(dossier_linked_path(current_instructeur, dossier), class: 'cell-link') do
                 = status_badge(dossier.state)
diff --git a/db/migrate/20210419100831_add_deleted_user_email_never_send_to_dossiers.rb b/db/migrate/20210419100831_add_deleted_user_email_never_send_to_dossiers.rb
new file mode 100644
index 000000000..8238f3e9c
--- /dev/null
+++ b/db/migrate/20210419100831_add_deleted_user_email_never_send_to_dossiers.rb
@@ -0,0 +1,5 @@
+class AddDeletedUserEmailNeverSendToDossiers < ActiveRecord::Migration[6.1]
+  def change
+    add_column :dossiers, :deleted_user_email_never_send, :string
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 44108f050..09d1a2239 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2021_04_28_104228) do
+ActiveRecord::Schema.define(version: 2021_04_28_114228) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -275,6 +275,7 @@ ActiveRecord::Schema.define(version: 2021_04_28_104228) do
     t.datetime "last_commentaire_updated_at"
     t.string "api_entreprise_job_exceptions", array: true
     t.interval "conservation_extension", default: "PT0S"
+    t.string "deleted_user_email_never_send"
     t.index "to_tsvector('french'::regconfig, (search_terms || private_search_terms))", name: "index_dossiers_on_search_terms_private_search_terms", using: :gin
     t.index "to_tsvector('french'::regconfig, search_terms)", name: "index_dossiers_on_search_terms", using: :gin
     t.index ["archived"], name: "index_dossiers_on_archived"
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 459fbae5d..6ad1040b9 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -263,13 +263,16 @@ describe User, type: :model do
 
   describe '#can_be_deleted?' do
     let(:user) { create(:user) }
+    let(:administrateur) { create(:administrateur) }
+    let(:instructeur) { create(:instructeur) }
+    let(:expert) { create(:expert) }
 
     subject { user.can_be_deleted? }
 
     context 'when the user has a dossier in instruction' do
       let!(:dossier) { create(:dossier, :en_instruction, user: user) }
 
-      it { is_expected.to be false }
+      it { is_expected.to be true }
     end
 
     context 'when the user has no dossier in instruction' do
@@ -278,19 +281,19 @@ describe User, type: :model do
 
     context 'when the user is an administrateur' do
       it 'cannot be deleted' do
-        administrateur = create(:administrateur)
-        user = administrateur.user
-
-        expect(user.can_be_deleted?).to be_falsy
+        expect(administrateur.user.can_be_deleted?).to be_falsy
       end
     end
 
     context 'when the user is an instructeur' do
       it 'cannot be deleted' do
-        instructeur = create(:instructeur)
-        user = instructeur.user
+        expect(instructeur.user.can_be_deleted?).to be_falsy
+      end
+    end
 
-        expect(user.can_be_deleted?).to be_falsy
+    context 'when the user is an expert' do
+      it 'cannot be deleted' do
+        expect(expert.user.can_be_deleted?).to be_falsy
       end
     end
   end
@@ -299,14 +302,7 @@ describe User, type: :model do
     let(:super_admin) { create(:super_admin) }
     let(:user) { create(:user) }
 
-    context 'with a dossier in instruction' do
-      let!(:dossier_en_instruction) { create(:dossier, :en_instruction, user: user) }
-      it 'raises' do
-        expect { user.delete_and_keep_track_dossiers(super_admin) }.to raise_error(RuntimeError)
-      end
-    end
-
-    context 'without a dossier in instruction' do
+    context 'without a dossier with processing strted' do
       let!(:dossier_en_construction) { create(:dossier, :en_construction, user: user) }
       let!(:dossier_brouillon) { create(:dossier, user: user) }
 
@@ -321,28 +317,39 @@ describe User, type: :model do
       end
 
       context 'with a discarded dossier' do
-        let!(:dossier_cache) do
-          create(:dossier, :en_construction, user: user)
-        end
-        let!(:dossier_from_another_user) do
-          create(:dossier, :en_construction, user: create(:user))
-        end
+        let(:dossier_to_discard) { create(:dossier, :en_construction, user: user) }
+        let!(:dossier_from_another_user) { create(:dossier, :en_construction, user: create(:user)) }
 
         it "keep track of dossiers and delete user" do
-          dossier_cache.discard_and_keep_track!(super_admin, :user_request)
+          dossier_to_discard.discard_and_keep_track!(super_admin, :user_request)
           user.delete_and_keep_track_dossiers(super_admin)
 
           expect(DeletedDossier.find_by(dossier_id: dossier_en_construction)).to be_present
           expect(DeletedDossier.find_by(dossier_id: dossier_brouillon)).to be_nil
+          expect(Dossier.find_by(id: dossier_from_another_user.id)).to be_present
           expect(User.find_by(id: user.id)).to be_nil
         end
+      end
+    end
 
-        it "doesn't destroy dossiers of another user" do
-          dossier_cache.discard_and_keep_track!(super_admin, :user_request)
-          user.delete_and_keep_track_dossiers(super_admin)
+    context 'with dossiers with processing strted' do
+      let!(:dossier_en_instruction) { create(:dossier, :en_instruction, user: user) }
+      let!(:dossier_termine) { create(:dossier, :accepte, user: user) }
 
-          expect(Dossier.find_by(id: dossier_from_another_user.id)).to be_present
-        end
+      it "keep track of dossiers and delete user" do
+        user.delete_and_keep_track_dossiers(super_admin)
+
+        expect(dossier_en_instruction.reload).to be_present
+        expect(dossier_en_instruction.user).to be_nil
+        expect(dossier_en_instruction.user_email_for(:display)).to eq(user.email)
+        expect { dossier_en_instruction.user_email_for(:notification) }.to raise_error(RuntimeError)
+
+        expect(dossier_termine.reload).to be_present
+        expect(dossier_termine.user).to be_nil
+        expect(dossier_termine.user_email_for(:display)).to eq(user.email)
+        expect { dossier_termine.user_email_for(:notification) }.to raise_error(RuntimeError)
+
+        expect(User.find_by(id: user.id)).to be_nil
       end
     end
   end