diff --git a/.github/workflows/legacy.yml b/.github/workflows/legacy.yml
index 67f2952..38dfe36 100644
--- a/.github/workflows/legacy.yml
+++ b/.github/workflows/legacy.yml
@@ -22,7 +22,7 @@ concurrency:
 
 jobs:
   test:
-    name: Ruby ${{ matrix.ruby }} ${{ matrix.name_extra || '' }}
+    name: Ruby ${{ matrix.ruby }} and ${{ matrix.appraisal }} ${{ matrix.name_extra || '' }}
     if: "!contains(github.event.commits[0].message, '[ci skip]') && !contains(github.event.commits[0].message, '[skip ci]')"
     env: # $BUNDLE_GEMFILE must be set at the job level, so it is set for all steps
       BUNDLE_GEMFILE: ${{ github.workspace }}/gemfiles/${{ matrix.gemfile }}.gemfile
@@ -31,18 +31,64 @@ jobs:
       matrix:
         experimental: [false]
         rubygems:
-          - "2.7.11"
+          - "3.3.27"
         bundler:
           - none
         gemfile:
           - vanilla
-        ruby:
-          - "3.0"
-          - "2.7"
-          - "2.6"
-          - "2.5"
-          - "2.4"
-          - "2.3"
+        include:
+          - ruby: "3.0"
+            appraisal: "rails-7-1"
+          - ruby: "3.0"
+            appraisal: "rails-7-0"
+          - ruby: "3.0"
+            appraisal: "rails-6-1"
+          - ruby: "3.0"
+            appraisal: "rails-6-1"
+          - ruby: "2.7"
+            appraisal: "rails-7-1"
+          - ruby: "2.7"
+            appraisal: "rails-7-0"
+          - ruby: "2.7"
+            appraisal: "rails-6-1"
+          - ruby: "2.7"
+            appraisal: "rails-6-0"
+          - ruby: "2.7"
+            appraisal: "rails-5-2"
+          - ruby: "2.6"
+            appraisal: "rails-6-1"
+          - ruby: "2.6"
+            appraisal: "rails-6-0"
+          - ruby: "2.6"
+            appraisal: "rails-5-2"
+          - ruby: "2.5"
+            appraisal: "rails-6-1"
+          - ruby: "2.5"
+            appraisal: "rails-6-0"
+          - ruby: "2.5"
+            appraisal: "rails-5-2"
+          - ruby: "2.5"
+            appraisal: "rails-5-1"
+          - ruby: "2.4"
+            appraisal: "rails-5-2"
+          - ruby: "2.4"
+            appraisal: "rails-5-1"
+          - ruby: "2.4"
+            appraisal: "rails-5-0"
+          - ruby: "2.4"
+            appraisal: "rails-4-2"
+          - ruby: "2.3"
+            appraisal: "rails-5-2"
+          - ruby: "2.3"
+            appraisal: "rails-5-1"
+          - ruby: "2.3"
+            appraisal: "rails-5-0"
+          - ruby: "2.3"
+            appraisal: "rails-4-2"
+          - ruby: "2.3"
+            appraisal: "rails-4-1"
+          - ruby: "2.3"
+            appraisal: "rails-4-0"
     runs-on: ubuntu-20.04
     continue-on-error: ${{ matrix.experimental || endsWith(matrix.ruby, 'head') }}
     steps:
@@ -54,6 +100,10 @@ jobs:
           ruby-version: ${{ matrix.ruby }}
           rubygems: ${{ matrix.rubygems }}
           bundler: ${{ matrix.bundler }}
-          bundler-cache: true
-      - name: Run tests
-        run: bundle exec rake test
+          bundler-cache: false
+      - name: Bundle for Appraisal ${{ matrix.appraisal }}
+        run: bundle
+      - name: Install Appraisal ${{ matrix.appraisal }} dependencies
+        run: bundle exec appraisal ${{ matrix.appraisal }} bundle
+      - name: Run tests ${{ matrix.appraisal }}
+        run: bundle exec appraisal ${{ matrix.appraisal }} bundle exec rake test
diff --git a/.github/workflows/supported.yml b/.github/workflows/supported.yml
index 1ad6841..a16d6d4 100644
--- a/.github/workflows/supported.yml
+++ b/.github/workflows/supported.yml
@@ -41,24 +41,38 @@ jobs:
           - latest
         gemfile:
           - vanilla
-        ruby:
+        include:
+          - ruby: "3.3"
+            appraisal: "rails-7-1"
+          - ruby: "3.3"
+            appraisal: "rails-7-0"
+          - ruby: "3.2"
+            appraisal: "rails-7-1"
+          - ruby: "3.2"
+            appraisal: "rails-7-0"
           #- '3.1' - 3.1 tests are run by coverage.yml
-          - '3.2'
-          - '3.3'
-          - truffleruby
-          - jruby
-
+          - ruby: "truffleruby"
+            appraisal: "rails-7-1"
+          - ruby: "jruby"
+            appraisal: "rails-7-1"
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-
+      - uses: actions/cache@v4
+        id: cache
+        with:
+          path: path/to/dependencies
+          key: ${{ runner.os }}-${{matrix.ruby}}-${{matrix.appraisal}}-${{ hashFiles('gemfiles/*.gemfile.lock') }}
       - name: Setup Ruby & Bundle
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: "${{ matrix.ruby }}"
           rubygems: "${{ matrix.rubygems }}"
           bundler: "${{ matrix.bundler }}"
-          bundler-cache: true
-
-      - name: Run tests
-        run: bundle exec rake test
+          bundler-cache: false
+      - name: Bundle for Appraisal ${{ matrix.appraisal }}
+        run: bundle
+      - name: Install Appraisal ${{ matrix.appraisal }} dependencies
+        run: bundle exec appraisal ${{ matrix.appraisal }} bundle
+      - name: Run tests ${{ matrix.appraisal }}
+        run: bundle exec appraisal ${{ matrix.appraisal }} bundle exec rake test
diff --git a/.tool-versions b/.tool-versions
index c1c77c3..59511e1 100644
--- a/.tool-versions
+++ b/.tool-versions
@@ -1 +1 @@
-ruby 3.2.3
+ruby 2.7.8
diff --git a/Appraisals b/Appraisals
index 4c87d81..0231768 100644
--- a/Appraisals
+++ b/Appraisals
@@ -1,29 +1,102 @@
 # frozen_string_literal: true
 
+# NOTE(2024-04-24): Current release of rake v13 supports Ruby >= 2.3
+# NOTE(2024-04-24): Current release of json v2 supports Ruby >= 2.3
+
+# Compat: Ruby >= 1.9.3
+# Test Matrix:
+#   - Ruby 2.3
+appraise "rails-4-0" do
+  gem "actionmailer", "~> 4.0.13"
+  gem "railties", "~> 4.0.13"
+end
+
+# Compat: Ruby >= 1.9.3
+# Test Matrix:
+#   - Ruby 2.3
+appraise "rails-4-1" do
+  gem "actionmailer", "~> 4.1.16"
+  gem "railties", "~> 4.1.16"
+end
+
+# Compat: Ruby >= 1.9.3
+# Test Matrix:
+#   - Ruby 2.3
+#   - Ruby 2.4
 appraise "rails-4-2" do
-  gem "actionmailer", "~> 4.2.0"
-  gem "railties", "~> 4.2.0"
-  gem "json", "~> 2.0"
-  gem "rake", "~> 11.0"
+  gem "actionmailer", "~> 4.2.11.3"
+  gem "railties", "~> 4.2.11.3"
 end
 
+# Compat: Ruby >= 2.2.2
+# Test Matrix:
+#   - Ruby 2.3
+#   - Ruby 2.4
 appraise "rails-5-0" do
-  gem "actionmailer", "~> 5.0.0"
-  gem "railties", "~> 5.0.0"
-  gem "json", "~> 2.0"
-  gem "rake", "~> 12.0"
+  gem "actionmailer", "~> 5.0.7.2"
+  gem "railties", "~> 5.0.7.2"
 end
 
+# Compat: Ruby >= 2.2.2
+# Test Matrix:
+#   - Ruby 2.3
+#   - Ruby 2.4
+#   - Ruby 2.5
 appraise "rails-5-1" do
-  gem "actionmailer", "~> 5.1.0"
-  gem "railties", "~> 5.1.0"
-  gem "json", "~> 2.0"
-  gem "rake", "~> 12.0"
+  gem "actionmailer", "~> 5.1.7"
+  gem "railties", "~> 5.1.7"
 end
 
+# Compat: Ruby >= 2.2.2
+# Test Matrix:
+#   - Ruby 2.3
+#   - Ruby 2.4
+#   - Ruby 2.5
+#   - Ruby 2.6
+#   - Ruby 2.7
 appraise "rails-5-2" do
-  gem "actionmailer", "~> 5.2.0"
-  gem "railties", "~> 5.2.0"
-  gem "json", "~> 2.0"
-  gem "rake", "~> 12.0"
+  gem "actionmailer", "~> 5.2.8.1"
+  gem "railties", "~> 5.2.8.1"
+end
+
+# Compat: Ruby >= 2.5
+# Test Matrix:
+#   - Ruby 2.5
+#   - Ruby 2.6
+#   - Ruby 2.7
+appraise "rails-6-0" do
+  gem "actionmailer", "~> 6.0.6.1"
+  gem "railties", "~> 6.0.6.1"
+end
+
+# Compat: Ruby >= 2.5
+# Test Matrix:
+#   - Ruby 2.5
+#   - Ruby 2.6
+#   - Ruby 2.7
+#   - Ruby 3.0
+appraise "rails-6-1" do
+  gem "actionmailer", "~> 6.1.7.7"
+  gem "railties", "~> 6.1.7.7"
+end
+
+# Compat: Ruby >= 2.7
+# Test Matrix:
+#   - Ruby 2.7
+#   - Ruby 3.0
+#   - Ruby 3.1
+appraise "rails-7-0" do
+  gem "actionmailer", "~> 7.0.8.1"
+  gem "railties", "~> 7.0.8.1"
+end
+
+# Compat: Ruby >= 2.7
+# Test Matrix:
+#   - Ruby 2.7
+#   - Ruby 3.0
+#   - Ruby 3.1
+#   - Ruby 3.2
+appraise "rails-7-1" do
+  gem "actionmailer", "~> 7.1.3.2"
+  gem "railties", "~> 7.1.3.2"
 end
diff --git a/Gemfile b/Gemfile
index 1e7c8c2..9a2cfa0 100644
--- a/Gemfile
+++ b/Gemfile
@@ -7,6 +7,13 @@ git_source(:github) { |repo_name| "https://github.com/#{repo_name}" }
 # Specify your gem's dependencies in sanitize_email.gemspec
 gemspec
 
+# Appraisals is having a *rough* time upgrading to Ruby 3, and worse upgrading past bundler v2.3.
+# Changes in Bundler 2.4 and/or 2.5 are causing many issues, and that's why we use git,
+# as some of the issues are fixed there.
+# See - https://github.com/thoughtbot/appraisal/issues/214
+# See - https://github.com/thoughtbot/appraisal/issues/218
+gem "appraisal", "~> 2", github: "thoughtbot/appraisal"
+
 platform :mri do
   # Debugging
   gem "byebug", ">= 11"
diff --git a/Gemfile.lock b/Gemfile.lock
index 555e7b2..e3a7f2a 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,3 +1,12 @@
+GIT
+  remote: https://github.com/thoughtbot/appraisal
+  revision: f5e31c48a1dda036a2c13663fad1b657a0953f5d
+  specs:
+    appraisal (2.5.0)
+      bundler
+      rake
+      thor (>= 0.14.0)
+
 PATH
   remote: .
   specs:
@@ -83,10 +92,6 @@ GEM
       mutex_m
       tzinfo (~> 2.0)
     ansi (1.5.0)
-    appraisal (2.5.0)
-      bundler
-      rake
-      thor (>= 0.14.0)
     ast (2.4.2)
     base64 (0.2.0)
     bigdecimal (3.1.7)
@@ -158,6 +163,7 @@ GEM
       net-smtp
     marcel (1.0.4)
     mini_mime (1.1.5)
+    mini_portile2 (2.8.6)
     minitest (5.22.3)
     mutex_m (0.2.0)
     net-imap (0.4.10)
@@ -170,18 +176,11 @@ GEM
     net-smtp (0.5.0)
       net-protocol
     nio4r (2.7.1)
-    nokogiri (1.16.4-aarch64-linux)
-      racc (~> 1.4)
-    nokogiri (1.16.4-arm-linux)
+    nokogiri (1.16.4)
+      mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
     nokogiri (1.16.4-arm64-darwin)
       racc (~> 1.4)
-    nokogiri (1.16.4-x86-linux)
-      racc (~> 1.4)
-    nokogiri (1.16.4-x86_64-darwin)
-      racc (~> 1.4)
-    nokogiri (1.16.4-x86_64-linux)
-      racc (~> 1.4)
     parallel (1.24.0)
     parser (3.3.0.5)
       ast (~> 2.4.1)
@@ -236,7 +235,7 @@ GEM
       rainbow (>= 2.0, < 4.0)
       rexml (~> 3.1)
     regexp_parser (2.9.0)
-    reline (0.5.2)
+    reline (0.5.3)
       io-console (~> 0.5)
     rexml (3.2.6)
     rspec (3.13.0)
@@ -365,17 +364,14 @@ GEM
     zeitwerk (2.6.13)
 
 PLATFORMS
-  aarch64-linux
-  arm-linux
-  arm64-darwin
-  x86-linux
-  x86_64-darwin
-  x86_64-linux
+  arm64-darwin-23
+  ruby
 
 DEPENDENCIES
   actionmailer (>= 3)
-  appraisal (~> 2)
+  appraisal (~> 2)!
   byebug (>= 11)
+  json (~> 2.7)
   kettle-soup-cover (~> 1.0, >= 1.0.2)
   rails (>= 3.0, <= 8)
   rake (>= 12)
diff --git a/lib/sanitize_email/engine_v6.rb b/lib/sanitize_email/engine_v6.rb
index adba025..90df307 100644
--- a/lib/sanitize_email/engine_v6.rb
+++ b/lib/sanitize_email/engine_v6.rb
@@ -5,11 +5,11 @@
 
 module SanitizeEmail
   # For Rails >= 6.0
-  class EngineV5 < ::Rails::Engine
-    config.to_prepare do
+  class EngineV6 < ::Rails::Engine
+    config.to_prepare do |app|
       # For the reasoning behind the difference between v5 and v6 engines,
       #   - see: https://github.com/rails/rails/issues/36546#issuecomment-850888284
-      config.action_mailer.register_interceptor(SanitizeEmail::Bleach)
+      Rails.application.config.action_mailer.register_interceptor(SanitizeEmail::Bleach)
     end
   end
 end
diff --git a/sanitize_email.gemspec b/sanitize_email.gemspec
index 22742a0..cd2be06 100644
--- a/sanitize_email.gemspec
+++ b/sanitize_email.gemspec
@@ -58,6 +58,7 @@ Gem::Specification.new do |spec|
   # Development Dependencies
   spec.add_development_dependency("actionmailer", ">= 3")
   spec.add_development_dependency("appraisal", "~> 2")
+  spec.add_development_dependency("json", "~> 2.7")
   spec.add_development_dependency("rails", ">= 3.0", "<= 8")
   spec.add_development_dependency("rake", ">= 12")
   spec.add_development_dependency("rdoc", ">= 3.12")