diff --git a/.simplecov b/.simplecov
index b81ebfeb..efee8860 100644
--- a/.simplecov
+++ b/.simplecov
@@ -1,3 +1,7 @@
 if ENV['COVERAGE'] == 'on'
-  SimpleCov.start 'rails'
+  SimpleCov.start 'rails' do
+    add_group 'Policies', 'app/policies'
+    add_group 'Services', 'app/services'
+    add_group 'Serializers', 'app/serializers'
+  end
 end
diff --git a/config/environments/test.rb b/config/environments/test.rb
index 5f0b1ee2..d85899fd 100644
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -30,6 +30,7 @@ Metamaps::Application.configure do
   # The :test delivery method accumulates sent emails in the
   # ActionMailer::Base.deliveries array.
   config.action_mailer.delivery_method = :test
+  config.action_mailer.default_url_options = { host: 'localhost:3000' }
 
   # Print deprecation notices to the stderr
   config.active_support.deprecation = :stderr
diff --git a/spec/mailers/map_mailer_spec.rb b/spec/mailers/map_mailer_spec.rb
new file mode 100644
index 00000000..d4da119e
--- /dev/null
+++ b/spec/mailers/map_mailer_spec.rb
@@ -0,0 +1,17 @@
+require 'rails_helper'
+
+RSpec.describe MapMailer, type: :mailer do
+  let(:map) { create(:map) }
+  let(:inviter) { create(:user) }
+  let(:invitee) { create(:user) }
+  describe 'invite_to_edit_email' do
+    let(:mail) { described_class.invite_to_edit_email(map, inviter, invitee) }
+
+    it { expect(mail.from).to eq ['team@metamaps.cc'] }
+    it { expect(mail.to).to eq [invitee.email] }
+    it { expect(mail.subject).to match map.name }
+    it { expect(mail.body.encoded).to match inviter.name }
+    it { expect(mail.body.encoded).to match map.name }
+    it { expect(mail.body.encoded).to match map_url(map) }
+  end
+end