diff --git a/Gemfile b/Gemfile
index f0cb92cfae2..01861f1ffac 100644
--- a/Gemfile
+++ b/Gemfile
@@ -333,7 +333,7 @@ gem 'newrelic_rpm', '~> 3.16'
 
 gem 'octokit', '~> 4.6.2'
 
-gem 'mail_room', '~> 0.9.0'
+gem 'mail_room', '~> 0.9.1'
 
 gem 'email_reply_trimmer', '~> 0.1'
 gem 'html2text'
diff --git a/Gemfile.lock b/Gemfile.lock
index e0c600f64c0..2a3be763753 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -408,7 +408,7 @@ GEM
       nokogiri (>= 1.5.9)
     mail (2.6.4)
       mime-types (>= 1.16, < 4)
-    mail_room (0.9.0)
+    mail_room (0.9.1)
     memoist (0.15.0)
     method_source (0.8.2)
     mime-types (2.99.3)
@@ -909,7 +909,7 @@ DEPENDENCIES
   license_finder (~> 2.1.0)
   licensee (~> 8.0.0)
   loofah (~> 2.0.3)
-  mail_room (~> 0.9.0)
+  mail_room (~> 0.9.1)
   method_source (~> 0.8)
   minitest (~> 5.7.0)
   mousetrap-rails (~> 1.4.6)
diff --git a/changelogs/unreleased/1363-redo-mailroom-support.yml b/changelogs/unreleased/1363-redo-mailroom-support.yml
new file mode 100644
index 00000000000..8ed206f4fdb
--- /dev/null
+++ b/changelogs/unreleased/1363-redo-mailroom-support.yml
@@ -0,0 +1,4 @@
+---
+title: Redo internals of Incoming Mail Support
+merge_request: 9385
+author:
diff --git a/config/mail_room.yml b/config/mail_room.yml
index 774c5350a45..88d93d4bc6b 100644
--- a/config/mail_room.yml
+++ b/config/mail_room.yml
@@ -1,9 +1,6 @@
-# If you change this file in a Merge Request, please also create
-# a Merge Request on https://gitlab.com/gitlab-org/omnibus-gitlab/merge_requests
-#
 :mailboxes:
   <%
-    require_relative "lib/gitlab/mail_room" unless defined?(Gitlab::MailRoom)
+    require_relative "../lib/gitlab/mail_room" unless defined?(Gitlab::MailRoom)
     config = Gitlab::MailRoom.config
 
     if Gitlab::MailRoom.enabled?
diff --git a/lib/tasks/gitlab/check.rake b/lib/tasks/gitlab/check.rake
index 35c4194e87c..6102517e730 100644
--- a/lib/tasks/gitlab/check.rake
+++ b/lib/tasks/gitlab/check.rake
@@ -724,8 +724,11 @@ namespace :gitlab do
     def check_imap_authentication
       print "IMAP server credentials are correct? ... "
 
-      config_path = Rails.root.join('config', 'mail_room.yml')
-      config_file = YAML.load(ERB.new(File.read(config_path)).result)
+      config_path = Rails.root.join('config', 'mail_room.yml').to_s
+      erb = ERB.new(File.read(config_path))
+      erb.filename = config_path
+      config_file = YAML.load(erb.result)
+
       config = config_file[:mailboxes].first
 
       if config
diff --git a/spec/config/mail_room_spec.rb b/spec/config/mail_room_spec.rb
index 294fae95752..0b8ff006d22 100644
--- a/spec/config/mail_room_spec.rb
+++ b/spec/config/mail_room_spec.rb
@@ -8,7 +8,7 @@ describe 'mail_room.yml' do
 
   context 'when incoming email is disabled' do
     before do
-      ENV['MAIL_ROOM_GITLAB_CONFIG_FILE'] = Rails.root.join('spec/fixtures/mail_room_disabled.yml').to_s
+      ENV['MAIL_ROOM_GITLAB_CONFIG_FILE'] = Rails.root.join('spec/fixtures/config/mail_room_disabled.yml').to_s
       Gitlab::MailRoom.reset_config!
     end
 
@@ -26,7 +26,7 @@ describe 'mail_room.yml' do
     let(:gitlab_redis) { Gitlab::Redis.new(Rails.env) }
 
     before do
-      ENV['MAIL_ROOM_GITLAB_CONFIG_FILE'] = Rails.root.join('spec/fixtures/mail_room_enabled.yml').to_s
+      ENV['MAIL_ROOM_GITLAB_CONFIG_FILE'] = Rails.root.join('spec/fixtures/config/mail_room_enabled.yml').to_s
       Gitlab::MailRoom.reset_config!
     end
 
diff --git a/spec/fixtures/mail_room_disabled.yml b/spec/fixtures/config/mail_room_disabled.yml
similarity index 100%
rename from spec/fixtures/mail_room_disabled.yml
rename to spec/fixtures/config/mail_room_disabled.yml
diff --git a/spec/fixtures/mail_room_enabled.yml b/spec/fixtures/config/mail_room_enabled.yml
similarity index 100%
rename from spec/fixtures/mail_room_enabled.yml
rename to spec/fixtures/config/mail_room_enabled.yml