diff --git a/app/controllers/admin/cfps_controller.rb b/app/controllers/admin/cfps_controller.rb
index 5d660d16..119faf78 100644
--- a/app/controllers/admin/cfps_controller.rb
+++ b/app/controllers/admin/cfps_controller.rb
@@ -31,7 +31,7 @@ module Admin
       send_mail_on_cfp_dates_updates = @cfp.notify_on_cfp_date_update?
 
       if @cfp.update_attributes(cfp_params)
-        Mailbot.delay.send_on_cfp_dates_updates(@conference) if send_mail_on_cfp_dates_updates
+        Mailbot.send_on_cfp_dates_updates(@conference).deliver_later if send_mail_on_cfp_dates_updates
         redirect_to admin_conference_program_cfp_path(@conference.short_title),
                     notice: 'Call for papers successfully updated.'
       else
diff --git a/app/controllers/admin/conference_controller.rb b/app/controllers/admin/conference_controller.rb
index dd520157..78fd68b4 100644
--- a/app/controllers/admin/conference_controller.rb
+++ b/app/controllers/admin/conference_controller.rb
@@ -85,7 +85,7 @@ module Admin
       send_mail_on_conf_update = @conference.notify_on_dates_changed?
 
       if @conference.update_attributes(conference_params)
-        Mailbot.delay.conference_date_update_mail(@conference) if send_mail_on_conf_update
+        Mailbot.conference_date_update_mail(@conference).deliver_later if send_mail_on_conf_update
         redirect_to edit_admin_conference_path(id: @conference.short_title),
                     notice: 'Conference was successfully updated.'
       else
diff --git a/app/controllers/admin/programs_controller.rb b/app/controllers/admin/programs_controller.rb
index c0d20644..a4bcefba 100644
--- a/app/controllers/admin/programs_controller.rb
+++ b/app/controllers/admin/programs_controller.rb
@@ -14,7 +14,7 @@ module Admin
       send_mail_on_schedule_public = @program.notify_on_schedule_public?
 
       if @program.update_attributes(program_params)
-        Mailbot.delay.send_on_schedule_public(@conference) if send_mail_on_schedule_public
+        Mailbot.send_on_schedule_public(@conference).deliver_later if send_mail_on_schedule_public
         redirect_to admin_conference_program_path(@conference.short_title),
                     notice: 'The program was successfully updated.'
       else
diff --git a/app/controllers/admin/registration_periods_controller.rb b/app/controllers/admin/registration_periods_controller.rb
index 85a7eef4..727f15a8 100644
--- a/app/controllers/admin/registration_periods_controller.rb
+++ b/app/controllers/admin/registration_periods_controller.rb
@@ -12,7 +12,7 @@ module Admin
       send_mail_on_reg_update = @conference.notify_on_registration_dates_changed?
 
       if @registration_period.save
-        Mailbot.delay.conference_registration_date_update_mail(@conference) if send_mail_on_reg_update
+        Mailbot.conference_registration_date_update_mail(@conference).deliver_later if send_mail_on_reg_update
         redirect_to admin_conference_registration_period_path(@conference.short_title),
                     notice: 'Registration Period successfully updated.'
       else
@@ -32,7 +32,7 @@ module Admin
       send_mail_on_reg_update = @conference.notify_on_registration_dates_changed?
 
       if @registration_period.update(registration_period_params)
-        Mailbot.delay.conference_registration_date_update_mail(@conference) if send_mail_on_reg_update
+        Mailbot.conference_registration_date_update_mail(@conference).deliver_later if send_mail_on_reg_update
         redirect_to admin_conference_registration_period_path(@conference.short_title),
                     notice: 'Registration Period successfully updated.'
       else
diff --git a/app/models/comment.rb b/app/models/comment.rb
index c699f18a..7449b051 100644
--- a/app/models/comment.rb
+++ b/app/models/comment.rb
@@ -56,6 +56,6 @@ class Comment < ActiveRecord::Base
   private
 
   def send_notification
-    Mailbot.delay.send_notification_email_for_comment(self)
+    Mailbot.send_notification_email_for_comment(self).deliver_later
   end
 end
diff --git a/app/models/event.rb b/app/models/event.rb
index 6e42ad99..d8652c90 100644
--- a/app/models/event.rb
+++ b/app/models/event.rb
@@ -112,7 +112,7 @@ class Event < ActiveRecord::Base
         program.conference.email_settings.confirmed_without_registration_body  &&
         program.conference.email_settings.confirmed_without_registration_subject
       if program.conference.registrations.where(user_id: submitter.id).first.nil?
-        Mailbot.delay.confirm_reminder_mail(self)
+        Mailbot.confirm_reminder_mail(self).deliver_later
       end
     end
   end
@@ -122,7 +122,7 @@ class Event < ActiveRecord::Base
         program.conference.email_settings.accepted_body &&
         program.conference.email_settings.accepted_subject &&
         !options[:send_mail].blank?
-      Mailbot.delay.acceptance_mail(self)
+      Mailbot.acceptance_mail(self).deliver_later
     end
   end
 
@@ -131,7 +131,7 @@ class Event < ActiveRecord::Base
         program.conference.email_settings.rejected_body &&
         program.conference.email_settings.rejected_subject &&
         !options[:send_mail].blank?
-      Mailbot.delay.rejection_mail(self)
+      Mailbot.rejection_mail(self).deliver_later
     end
   end
 
diff --git a/app/models/registration.rb b/app/models/registration.rb
index 0d314c3d..2026af56 100644
--- a/app/models/registration.rb
+++ b/app/models/registration.rb
@@ -45,7 +45,7 @@ class Registration < ActiveRecord::Base
 
   def send_registration_mail
     if conference.email_settings.send_on_registration?
-      Mailbot.delay.registration_mail(conference, user)
+      Mailbot.registration_mail(conference, user).deliver_later
     end
   end
 
diff --git a/app/models/venue.rb b/app/models/venue.rb
index 2fcbf961..ac138c23 100644
--- a/app/models/venue.rb
+++ b/app/models/venue.rb
@@ -30,7 +30,7 @@ class Venue < ActiveRecord::Base
   private
 
   def send_mail_notification
-    Mailbot.delay.send_email_on_venue_updated(conference) if notify_on_venue_changed?
+    Mailbot.send_email_on_venue_updated(conference).deliver_later if notify_on_venue_changed?
   end
 
   def notify_on_venue_changed?
diff --git a/config/application.rb b/config/application.rb
index 6f863991..9123e5bb 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -64,5 +64,6 @@ module Osem
     # Errors raised within `after_rollback`/`after_commit` propagate normally
     # like in other Active Record callbacks.
     config.active_record.raise_in_transactional_callbacks = true
+    config.active_job.queue_adapter = :delayed_job
   end
 end