diff --git a/.circleci/config.yml b/.circleci/config.yml
index 61b1e72..edc5d1d 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -11,11 +11,6 @@ orbs:
   ruby: circleci/ruby@2.0.0
 
 references:
-  restore_bundle_cache: &restore_bundle_cache
-    restore_cache:
-      keys:
-        - truemail-{{ checksum "truemail.gemspec" }}
-
   bundle_install: &bundle_install
     run:
       name: Installing gems
@@ -23,17 +18,10 @@ references:
             bundle config set --local path '~/vendor/bundle'
             bundle install
 
-  save_bundle_cache: &save_bundle_cache
-    save_cache:
-      key: truemail-{{ checksum "truemail.gemspec" }}
-      paths:
-        - ~/vendor/bundle
-
   install_system_dependencies: &install_system_dependencies
     run:
       name: Installing system dependencies
-      command: |
-            bundle exec smtp_mock -s -i ~
+      command: bundle exec smtp_mock -s -i ~
 
   install_linters: &install_linters
     run:
@@ -53,17 +41,20 @@ references:
             curl -L https://codeclimate.com/downloads/test-reporter/test-reporter-latest-linux-amd64 > ./cc-test-reporter
             chmod +x ./cc-test-reporter
 
+  use_latest_bundler: &use_latest_bundler
+    run:
+      name: Using latest bundler
+      command: gem install bundler
+
   use_latest_gemspec: &use_latest_gemspec
     run:
       name: Using latest gemspec
-      command: |
-            cp .circleci/gemspecs/latest truemail.gemspec
+      command: cp .circleci/gemspecs/latest truemail.gemspec
 
   use_compatible_gemspec: &use_compatible_gemspec
     run:
       name: Using compatible gemspec
-      command: |
-            cp .circleci/gemspecs/compatible truemail.gemspec
+      command: cp .circleci/gemspecs/compatible truemail.gemspec
 
 jobs:
   linters-ruby:
@@ -76,10 +67,9 @@ jobs:
     steps:
       - checkout
 
+      - <<: *use_latest_bundler
       - <<: *use_latest_gemspec
-      - <<: *restore_bundle_cache
       - <<: *bundle_install
-      - <<: *save_bundle_cache
       - <<: *install_linters
 
       - run:
@@ -112,10 +102,9 @@ jobs:
     steps:
       - checkout
 
+      - <<: *use_latest_bundler
       - <<: *use_latest_gemspec
-      - <<: *restore_bundle_cache
       - <<: *bundle_install
-      - <<: *save_bundle_cache
       - <<: *install_system_dependencies
       - <<: *install_codeclimate_reporter
 
@@ -163,7 +152,7 @@ jobs:
           name: Running compatibility tests
           command: bundle exec rspec
 
-  building-rubygems-dependencies-from-ruby:
+  rubygems-deps-ruby:
     parameters:
       ruby-version:
         type: string
@@ -177,7 +166,7 @@ jobs:
           name: Building rubygems dependencies from default gemspec on minimal Ruby version
           command: bundle install
 
-  releasing-gem-from-ruby:
+  releasing-gem-ruby:
     parameters:
       ruby-version:
         type: string
@@ -210,16 +199,16 @@ workflows:
           matrix:
             parameters:
               ruby-version: ["2.5", "2.6", "2.7", "3.0", "3.1"]
-      - building-rubygems-dependencies-from-ruby:
+      - rubygems-deps-ruby:
           matrix:
             parameters:
               ruby-version: ["2.5"]
-      - releasing-gem-from-ruby:
+      - releasing-gem-ruby:
           requires:
             - linters-ruby
             - tests-ruby
             - compatibility-ruby
-            - building-rubygems-dependencies-from-ruby
+            - rubygems-deps-ruby
           matrix:
             parameters:
               ruby-version: ["2.5"]
diff --git a/.circleci/gemspecs/latest b/.circleci/gemspecs/latest
index d0af5bc..255af85 100644
--- a/.circleci/gemspecs/latest
+++ b/.circleci/gemspecs/latest
@@ -26,13 +26,13 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'json_matchers', '~> 0.11.1'
   spec.add_development_dependency 'pry-byebug', '~> 3.10', '>= 3.10.1'
   spec.add_development_dependency 'rake', '~> 13.0', '>= 13.0.6'
-  spec.add_development_dependency 'reek', '~> 6.1', '>= 6.1.3'
+  spec.add_development_dependency 'reek', '~> 6.1', '>= 6.1.4'
   spec.add_development_dependency 'rspec', '~> 3.12'
-  spec.add_development_dependency 'rubocop', '~> 1.42'
-  spec.add_development_dependency 'rubocop-performance', '~> 1.15', '>= 1.15.2'
-  spec.add_development_dependency 'rubocop-rspec', '~> 2.16'
+  spec.add_development_dependency 'rubocop', '~> 1.45', '>= 1.45.1'
+  spec.add_development_dependency 'rubocop-performance', '~> 1.16'
+  spec.add_development_dependency 'rubocop-rspec', '~> 2.18', '>= 2.18.1'
   spec.add_development_dependency 'simplecov', '~> 0.22.0'
   spec.add_development_dependency 'smtp_mock', '~> 1.3', '>= 1.3.4'
-  spec.add_development_dependency 'truemail-rspec', '~> 1.0'
+  spec.add_development_dependency 'truemail-rspec', '~> 1.1'
   spec.add_development_dependency 'webmock', '~> 3.18', '>= 3.18.1'
 end
diff --git a/.codeclimate.yml b/.codeclimate.yml
index efdbcc3..ba38e50 100644
--- a/.codeclimate.yml
+++ b/.codeclimate.yml
@@ -9,7 +9,7 @@ checks:
 plugins:
   rubocop:
     enabled: true
-    channel: rubocop-1-42
+    channel: rubocop-1-45
     config:
       file: .circleci/linter_configs/.rubocop.yml
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index eb90c5a..8852ad8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,15 @@
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [3.0.6] - 2023.02.17
+
+### Updated
+
+- Updated development dependencies
+- Updated gemspecs
+- Updated `rubocop`/`codeclimate`/`circleci` configs
+- Updated gem version
+
 ## [3.0.5] - 2023.01.12
 
 ### Added
diff --git a/lib/truemail/version.rb b/lib/truemail/version.rb
index c37f52f..cbde38d 100644
--- a/lib/truemail/version.rb
+++ b/lib/truemail/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Truemail
-  VERSION = '3.0.5'
+  VERSION = '3.0.6'
 end
diff --git a/truemail.gemspec b/truemail.gemspec
index c12b157..e4f7198 100644
--- a/truemail.gemspec
+++ b/truemail.gemspec
@@ -26,6 +26,7 @@ Gem::Specification.new do |spec|
   spec.files = `git ls-files -z`.split("\x0").select { |f| f.match(%r{^(bin|lib)/|.ruby-version|truemail.gemspec|LICENSE}) }
   spec.require_paths = %w[lib]
 
+  spec.add_runtime_dependency 'net-smtp', '~> 0.3.3' if ::Gem::Version.new(::RUBY_VERSION) >= ::Gem::Version.new('3.1.0')
   spec.add_runtime_dependency 'simpleidn', '~> 0.2.1'
 
   spec.add_development_dependency 'dns_mock', '~> 1.5', '>= 1.5.15'
@@ -34,6 +35,6 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'rake', '~> 13.0', '>= 13.0.6'
   spec.add_development_dependency 'rspec', '~> 3.12'
   spec.add_development_dependency 'smtp_mock', '~> 1.3', '>= 1.3.4'
-  spec.add_development_dependency 'truemail-rspec', '~> 1.0'
+  spec.add_development_dependency 'truemail-rspec', '~> 1.1'
   spec.add_development_dependency 'webmock', '~> 3.18', '>= 3.18.1'
 end