diff --git a/app/jobs/unqueue_message_job.rb b/app/jobs/unqueue_message_job.rb
index 2fb94e9..ea7d40d 100644
--- a/app/jobs/unqueue_message_job.rb
+++ b/app/jobs/unqueue_message_job.rb
@@ -455,6 +455,7 @@ class UnqueueMessageJob < Postal::Job
 
   private
 
+  # rubocop:disable Naming/MemoizedInstanceVariableName
   def cached_sender(klass, *args)
     @sender ||= begin
       sender = klass.new(*args)
@@ -462,5 +463,6 @@ class UnqueueMessageJob < Postal::Job
       sender
     end
   end
+  # rubocop:enable Naming/MemoizedInstanceVariableName
 
 end
diff --git a/app/models/incoming_message_prototype.rb b/app/models/incoming_message_prototype.rb
index b4594f2..6c9ad0d 100644
--- a/app/models/incoming_message_prototype.rb
+++ b/app/models/incoming_message_prototype.rb
@@ -24,11 +24,11 @@ class IncomingMessagePrototype
   end
 
   def route
-    @routes ||= if @to.present?
-                  uname, domain = @to.split("@", 2)
-                  uname, _tag = uname.split("+", 2)
-                  @server.routes.includes(:domain).where(domains: { name: domain }, name: uname).first
-                end
+    @route ||= if @to.present?
+                 uname, domain = @to.split("@", 2)
+                 uname, _tag = uname.split("+", 2)
+                 @server.routes.includes(:domain).where(domains: { name: domain }, name: uname).first
+               end
   end
 
   def attachments
diff --git a/app/models/outgoing_message_prototype.rb b/app/models/outgoing_message_prototype.rb
index d1bff40..a2abd99 100644
--- a/app/models/outgoing_message_prototype.rb
+++ b/app/models/outgoing_message_prototype.rb
@@ -49,13 +49,11 @@ class OutgoingMessagePrototype
   end
 
   def find_domain
-    @domain ||= begin
-      domain = @server.authenticated_domain_for_address(@from)
-      if @server.allow_sender? && domain.nil?
-        domain = @server.authenticated_domain_for_address(@sender)
-      end
-      domain || :none
+    domain = @server.authenticated_domain_for_address(@from)
+    if @server.allow_sender? && domain.nil?
+      domain = @server.authenticated_domain_for_address(@sender)
     end
+    domain || :none
   end
 
   def to_addresses
diff --git a/lib/postal/query_string.rb b/lib/postal/query_string.rb
index 75df96a..3ca28c0 100644
--- a/lib/postal/query_string.rb
+++ b/lib/postal/query_string.rb
@@ -8,12 +8,12 @@ module Postal
     end
 
     def [](value)
-      to_hash[value.to_s]
+      hash[value.to_s]
     end
 
-    delegate :empty?, to: :to_hash
+    delegate :empty?, to: :hash
 
-    def to_hash
+    def hash
       @hash ||= @string.scan(/([a-z]+):\s*(?:(\d{2,4}-\d{2}-\d{2}\s\d{2}:\d{2})|"(.*?)"|(.*?))(\s|\z)/).each_with_object({}) do |(key, date, string_with_spaces, value), hash|
         if date
           actual_value = date
diff --git a/lib/postal/worker.rb b/lib/postal/worker.rb
index c9ef066..c790f1b 100644
--- a/lib/postal/worker.rb
+++ b/lib/postal/worker.rb
@@ -202,7 +202,7 @@ module Postal
       end
 
       def job_channel
-        @channel ||= Postal::RabbitMQ.create_channel
+        @job_channel ||= Postal::RabbitMQ.create_channel
       end
 
       def job_queue(name)
diff --git a/spec/lib/postal/query_string_spec.rb b/spec/lib/postal/query_string_spec.rb
index 88e9609..6be6283 100644
--- a/spec/lib/postal/query_string_spec.rb
+++ b/spec/lib/postal/query_string_spec.rb
@@ -5,40 +5,40 @@ require "rails_helper"
 describe Postal::QueryString do
   it "should work with a single item" do
     qs = Postal::QueryString.new("to: test@example.com")
-    expect(qs.to_hash["to"]).to eq "test@example.com"
+    expect(qs.hash["to"]).to eq "test@example.com"
   end
 
   it "should work with a multiple items" do
     qs = Postal::QueryString.new("to: test@example.com from: another@example.com")
-    expect(qs.to_hash["to"]).to eq "test@example.com"
-    expect(qs.to_hash["from"]).to eq "another@example.com"
+    expect(qs.hash["to"]).to eq "test@example.com"
+    expect(qs.hash["from"]).to eq "another@example.com"
   end
 
   it "should not require a space after the field name" do
     qs = Postal::QueryString.new("to:test@example.com from:another@example.com")
-    expect(qs.to_hash["to"]).to eq "test@example.com"
-    expect(qs.to_hash["from"]).to eq "another@example.com"
+    expect(qs.hash["to"]).to eq "test@example.com"
+    expect(qs.hash["from"]).to eq "another@example.com"
   end
 
   it "should return nil when it receives blank" do
     qs = Postal::QueryString.new("to:[blank]")
-    expect(qs.to_hash["to"]).to eq nil
+    expect(qs.hash["to"]).to eq nil
   end
 
   it "should handle dates with spaces" do
     qs = Postal::QueryString.new("date: 2017-02-12 15:20")
-    expect(qs.to_hash["date"]).to eq("2017-02-12 15:20")
+    expect(qs.hash["date"]).to eq("2017-02-12 15:20")
   end
 
   it "should return an array for multiple items" do
     qs = Postal::QueryString.new("to: test@example.com to: another@example.com")
-    expect(qs.to_hash["to"]).to be_a(Array)
-    expect(qs.to_hash["to"][0]).to eq "test@example.com"
-    expect(qs.to_hash["to"][1]).to eq "another@example.com"
+    expect(qs.hash["to"]).to be_a(Array)
+    expect(qs.hash["to"][0]).to eq "test@example.com"
+    expect(qs.hash["to"][1]).to eq "another@example.com"
   end
 
   it "should work with a z in the string" do
     qs = Postal::QueryString.new("to: testaz@example.com")
-    expect(qs.to_hash["to"]).to eq "testaz@example.com"
+    expect(qs.hash["to"]).to eq "testaz@example.com"
   end
 end