diff --git a/app/controllers/concerns/conditional_user_mailer.rb b/app/controllers/concerns/conditional_user_mailer.rb
new file mode 100644
index 0000000..aa7622b
--- /dev/null
+++ b/app/controllers/concerns/conditional_user_mailer.rb
@@ -0,0 +1,35 @@
+module ConditionalUserMailer
+  extend ActiveSupport::Concern
+
+  # Adds following methods as class methods for the class that include this module
+  included do
+    # Executes a given block passed if the recipient user has the preference email key enabled
+    # @param recipients {User | Enumerable } User object or any object that includes Enumerable class
+    # @param key {String} - A key (dot notation) whose value is true/false and belongs to prefences.email (see config/branding.yml)
+    def deliver_if(recipients: [], key:)
+      raise(ArgumentError, 'key must be String') unless key.is_a?(String)
+      if block_given?
+        split_key = key.split('.')
+        if !recipients.respond_to?(:each)
+          recipients = Array(recipients)
+        end
+        recipients.each do |r|
+          if r.respond_to?(:get_preferences)
+            email_hash = r.get_preferences('email')
+            should_deliver = split_key.reduce(email_hash) do |m,o|
+              if m.is_a?(Hash)
+                m[o.to_sym]
+              else
+                break
+              end
+            end
+            yield r if should_deliver.is_a?(TrueClass)
+          end
+        end
+        true
+      else  # Block not given
+        false
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/app/controllers/notes_controller.rb b/app/controllers/notes_controller.rb
index d128345..cce8567 100644
--- a/app/controllers/notes_controller.rb
+++ b/app/controllers/notes_controller.rb
@@ -1,9 +1,9 @@
 class NotesController < ApplicationController
+  include ConditionalUserMailer
+  require "pp"
   after_action :verify_authorized
   respond_to :html
 
-  require "pp"
-
   def create
     @note = Note.new
     @note.user_id = params[:note][:user_id]
@@ -36,6 +36,12 @@
 
     if @note.save
       @status = true
+      answer = @note.answer
+      plan = answer.plan
+      owner = plan.owner
+      deliver_if(recipients: owner, key: 'users.new_comment') do |r|
+        UserMailer.new_comment(r, plan).deliver_now()
+      end
       @notice = success_message(_('comment'), _('created'))
       render(json: {
         "notes" => {
diff --git a/app/controllers/plans_controller.rb b/app/controllers/plans_controller.rb
index a38cd5d..a5ee45a 100644
--- a/app/controllers/plans_controller.rb
+++ b/app/controllers/plans_controller.rb
@@ -1,4 +1,5 @@
 class PlansController < ApplicationController
+  include ConditionalUserMailer
   require 'pp'
   helper PaginableHelper
   helper SettingsTemplateHelper
@@ -312,7 +313,9 @@
       if plan.visibility_allowed?
         plan.visibility = plan_params[:visibility]
         if plan.save
-          UserMailer.plan_visibility(User.find_by(email: "jose.lloret@ed.ac.uk"),plan).deliver_now()
+          deliver_if(recipients: plan.owner_and_coowners, key: 'owners_and_coowners.visibility_changed') do |r|
+            UserMailer.plan_visibility(r,plan).deliver_now()
+          end
           render status: :ok, json: { msg: success_message(_('plan\'s visibility'), _('changed')) }
         else
           render status: :internal_server_error, json: { msg: _('Error raised while saving the visibility for plan id %{plan_id}') %{ :plan_id => params[:id]} }
diff --git a/app/controllers/roles_controller.rb b/app/controllers/roles_controller.rb
index 58b34f6..05ee86c 100644
--- a/app/controllers/roles_controller.rb
+++ b/app/controllers/roles_controller.rb
@@ -1,4 +1,5 @@
 class RolesController < ApplicationController
+  include ConditionalUserMailer
   respond_to :html
   after_action :verify_authorized
 
@@ -27,7 +28,11 @@
           message += _('Plan shared with %{email}.') % {email: user.email}
           @role.user = user
           if @role.save
-            if registered then UserMailer.sharing_notification(@role, current_user).deliver_now end
+            if registered
+              deliver_if(recipients: user, key: 'users.added_as_coowner') do |r|
+                UserMailer.sharing_notification(@role, r).deliver_now
+              end
+            end
             flash[:notice] = message
           else
             flash[:alert] = failed_create_error(@role, _('role'))
@@ -105,4 +110,4 @@
     end
   end
 
-end
+end
\ No newline at end of file
diff --git a/app/models/note.rb b/app/models/note.rb
index e20cc04..4341c2a 100644
--- a/app/models/note.rb
+++ b/app/models/note.rb
@@ -11,10 +11,4 @@
                   :answer, :user, :as => [:default, :admin]
                   
   validates :text, :answer, :user, presence: {message: _("can't be blank")}
-
-  # Active Record Callbacks
-  after_create do
-    # Sends an email to the plan owner regarding a new comment created by new note user
-    UserMailer.new_comment(self.user, self.answer.plan).deliver_now()
-  end
 end
diff --git a/app/models/plan.rb b/app/models/plan.rb
index fe5bc49..cdc9882 100644
--- a/app/models/plan.rb
+++ b/app/models/plan.rb
@@ -1,5 +1,5 @@
 class Plan < ActiveRecord::Base
-
+  include ConditionalUserMailer
   before_validation :set_creation_defaults
 
   ##
@@ -216,8 +216,9 @@
       if user.org.contact_email.present?
         admins << User.new(email: user.org.contact_email, firstname: user.org.contact_name)
       end
-      admins.each do |admin|
-        UserMailer.feedback_notification(admin, self, user).deliver_now
+
+      deliver_if(recipients: admins, key: 'admins.feedback_requested') do |r|
+        UserMailer.feedback_notification(r, self, user).deliver_now
       end
       true
     else
diff --git a/app/models/user.rb b/app/models/user.rb
index ea34e83..c028a92 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -266,7 +266,7 @@
     if self.pref.present? && self.pref.settings[key.to_s].present?
       return self.pref.settings[key.to_s].deep_symbolize_keys
     elsif Pref.default_settings
-      return Pref.default_settings[key]
+      return Pref.default_settings[key.to_sym] || Pref.default_settings[key.to_s]
     else
       return nil
     end
diff --git a/test/unit/concerns/conditional_user_mailer_test.rb b/test/unit/concerns/conditional_user_mailer_test.rb
new file mode 100644
index 0000000..9700ae1
--- /dev/null
+++ b/test/unit/concerns/conditional_user_mailer_test.rb
@@ -0,0 +1,67 @@
+require 'test_helper'
+
+class ConditionalUserMailerTest < ActiveSupport::TestCase
+  include ConditionalUserMailer
+
+  def save_email_users_new_comment(user, value)
+    settings = Pref.default_settings
+    settings[:email][:users][:new_comment] = value
+    Pref.new(user: user, settings: settings).save
+  end
+
+  setup do
+    @super_admin = User.find_by(email: 'super_admin@example.com')
+    @funder = User.find_by(email: 'funder_admin@example.com')
+    @org_admin = User.find_by(email: 'org_admin@example.com')
+    @org_user = User.find_by(email: 'org_user@example.com')
+  end
+  test 'raises ArgumentError for a non-valid key' do
+    e = assert_raises(ArgumentError) do
+      deliver_if(recipients: @super_admin, key: nil)
+    end
+    assert_equal('key must be String', e.message)
+  end
+  test 'returns false when a block is not given' do
+    assert_equal(deliver_if(recipients: @super_admin, key: 'foo'), false)
+  end
+  test 'block is NOT executed when an email preference does not exist' do
+    block = false
+    assert_equal(deliver_if(recipients: @super_admin, key: 'foo'){ block = true }, true)
+    refute block
+  end
+  test 'block is NOT executed when an email preference is disabled' do
+    save_email_users_new_comment(@super_admin, false)
+    block = false
+    assert_equal(deliver_if(recipients: @super_admin, key: 'users.new_comment') { block = true }, true)
+    refute block
+  end
+  test 'block is executed when an email preference is enabled' do
+    save_email_users_new_comment(@super_admin, true)
+    block = false
+    assert_equal(deliver_if(recipients: @super_admin, key: 'users.new_comment') { block = true }, true)
+    assert block
+  end
+  test 'block is executed for those users from an array with an email preference enabled' do
+    save_email_users_new_comment(@super_admin, true)
+    save_email_users_new_comment(@funder, false)
+    save_email_users_new_comment(@org_admin, false)
+    save_email_users_new_comment(@org_user, true)
+    block = {}
+    recipients = [ @super_admin, @funder, @org_admin, @org_user ]
+    assert_equal(deliver_if(recipients: recipients, key: 'users.new_comment') { |r| block[r.email] = true }, true)
+    assert_equal({ 'super_admin@example.com' => true, 'org_user@example.com' => true }, block)
+  end
+  test 'block is executed for those users from an ActiveRecord::Relation with an email preference enabled' do
+    users = User.where(id: [@super_admin.id, @funder.id, @org_admin.id, @org_user.id])
+    save_email_users_new_comment(users.first, true)
+    save_email_users_new_comment(users.second, false)
+    save_email_users_new_comment(users.third, false)
+    save_email_users_new_comment(users.fourth, true)
+    expected = {}
+    expected[users.first.email] = true
+    expected[users.fourth.email] = true
+    block = {}
+    assert_equal(deliver_if(recipients: users, key: 'users.new_comment'){ |r| block[r.email] = true }, true)
+    assert_equal(expected, block)
+  end
+end
\ No newline at end of file