openly fail when not delivering mail

app/mailers/application_mailer.rb

@@ -3,11 +3,6 @@ class ApplicationMailer < ActionMailer::Base
   default from: "demarches-simplifiees.fr <#{CONTACT_EMAIL}>"
   layout 'mailer'
 
-  # Don’t retry to send a message if the server rejects the recipient address
-  rescue_from Net::SMTPSyntaxError do |_error|
-    message.perform_deliveries = false
-  end
-
   # Attach the procedure logo to the email (if any).
   # Returns the attachment url.
   def attach_logo(procedure)

app/mailers/devise_user_mailer.rb

@@ -4,11 +4,6 @@ class DeviseUserMailer < Devise::Mailer
   include Devise::Controllers::UrlHelpers # Optional. eg. `confirmation_url`
   layout 'mailers/layout'
 
-  # Don’t retry to send a message if the server rejects the recipient address
-  rescue_from Net::SMTPSyntaxError do |_error|
-    message.perform_deliveries = false
-  end
-
   def template_paths
     ['devise_mailer']
   end

spec/mailers/application_mailer_spec.rb

@@ -3,16 +3,6 @@ RSpec.describe ApplicationMailer, type: :mailer do
     let(:dossier) { create(:dossier, procedure: build(:simple_procedure)) }
     subject { DossierMailer.notify_new_draft(dossier) }
 
-    describe 'invalid emails are not sent' do
-      before do
-        allow_any_instance_of(DossierMailer)
-          .to receive(:notify_new_draft)
-          .and_raise(Net::SMTPSyntaxError)
-      end
-
-      it { expect(subject.message).to be_an_instance_of(ActionMailer::Base::NullMail) }
-    end
-
     describe 'valid emails are sent' do
       it { expect(subject.message).not_to be_an_instance_of(ActionMailer::Base::NullMail) }
     end