diff --git a/README.md b/README.md
index ad48caf..3533e3a 100644
--- a/README.md
+++ b/README.md
@@ -280,14 +280,14 @@ Solid Errors _can_ send email notifications whenever an error occurs, if your ap
 
 There are two ways to configure email notifications. First, you can use environment variables:
 
-```ruby
-ENV["SOLIDERRORS_SEND_EMAILS"] = true # defaults to false
-ENV["SOLIDERRORS_EMAIL_FROM"] = "errors@myapp.com" # defaults to "solid_errors@noreply.com"
-ENV["SOLIDERRORS_EMAIL_TO"] = "devs@myapp.com" # no default, must be set
-ENV["SOLIDERRORS_EMAIL_SUBJECT_PREFIX"] = "[Application name][Environment]" # no default, optional
+```sh
+SOLIDERRORS_SEND_EMAILS=true # defaults to false
+SOLIDERRORS_EMAIL_FROM=errors@myapp.com # defaults to solid_errors@noreply.com
+SOLIDERRORS_EMAIL_TO=devs@myapp.com # no default, must be set
+SOLIDERRORS_EMAIL_SUBJECT_PREFIX="[Application name][Environment]" # no default, optional
 ```
 
-Second, you can set the values via the configuration object:
+Second, you can set the values via the configuration object, which takes precedence over the environment variables:
 
 ```ruby
 # Set authentication credentials and optional subject prefix for Solid Errors
diff --git a/lib/solid_errors.rb b/lib/solid_errors.rb
index 458ab4c..c4faa29 100644
--- a/lib/solid_errors.rb
+++ b/lib/solid_errors.rb
@@ -11,10 +11,7 @@ module SolidErrors
   mattr_accessor :base_controller_class, default: "::ActionController::Base"
   mattr_writer :username
   mattr_writer :password
-  mattr_accessor :send_emails, default: false
-  mattr_accessor :email_from, default: "solid_errors@noreply.com"
-  mattr_accessor :email_to
-  mattr_accessor :email_subject_prefix
+  mattr_writer :send_emails, :email_from, :email_to, :email_subject_prefix, default: nil
   mattr_accessor :email_every_occurrence, default: true
   # Builds the error email's subject, before email_subject_prefix. reason is :created or :reopened when
   # the occurrence opened its error, nil for any other occurrence, or the app's own reason when it sends the email itself
@@ -39,6 +36,23 @@ def password
       @password ||= ENV["SOLIDERRORS_PASSWORD"] || @@password
     end
 
+    # Each email setting falls back to its SOLIDERRORS_* environment variable when not configured
+    def send_emails
+      @@send_emails.nil? ? ActiveModel::Type::Boolean.new.cast(ENV["SOLIDERRORS_SEND_EMAILS"]) || false : @@send_emails
+    end
+
+    def email_from
+      @@email_from || ENV["SOLIDERRORS_EMAIL_FROM"] || "solid_errors@noreply.com"
+    end
+
+    def email_to
+      @@email_to || ENV["SOLIDERRORS_EMAIL_TO"]
+    end
+
+    def email_subject_prefix
+      @@email_subject_prefix || ENV["SOLIDERRORS_EMAIL_SUBJECT_PREFIX"]
+    end
+
     # Whether the errors database has every table and column this version reads and writes.
     # Assert it in your test suite to catch a schema change you haven't applied yet.
     def migrated?
diff --git a/test/solid_errors/email_configuration_test.rb b/test/solid_errors/email_configuration_test.rb
new file mode 100644
index 0000000..53a7b19
--- /dev/null
+++ b/test/solid_errors/email_configuration_test.rb
@@ -0,0 +1,44 @@
+require "test_helper"
+
+class SolidErrors::EmailConfigurationTest < ActiveSupport::TestCase
+  SETTINGS = %i[send_emails email_from email_to email_subject_prefix]
+  ENV_VARS = %w[SOLIDERRORS_SEND_EMAILS SOLIDERRORS_EMAIL_FROM SOLIDERRORS_EMAIL_TO SOLIDERRORS_EMAIL_SUBJECT_PREFIX]
+
+  setup do
+    @settings = SETTINGS.to_h { |name| [name, SolidErrors.class_variable_get(:"@@#{name}")] }
+    @env = ENV.to_h.slice(*ENV_VARS)
+    SETTINGS.each { |name| SolidErrors.public_send(:"#{name}=", nil) }
+  end
+
+  teardown do
+    @settings.each { |name, value| SolidErrors.public_send(:"#{name}=", value) }
+    ENV_VARS.each { |var| ENV.delete(var) }
+    ENV.update(@env)
+  end
+
+  test "email settings fall back to their environment variables" do
+    ENV.update(
+      "SOLIDERRORS_SEND_EMAILS" => "true",
+      "SOLIDERRORS_EMAIL_FROM" => "errors@example.com",
+      "SOLIDERRORS_EMAIL_TO" => "devs@example.com",
+      "SOLIDERRORS_EMAIL_SUBJECT_PREFIX" => "[App]"
+    )
+
+    assert_equal [true, "errors@example.com", "devs@example.com", "[App]"],
+      SETTINGS.map { |name| SolidErrors.public_send(name) }
+    assert SolidErrors.send_emails?
+  end
+
+  test "configured email settings win over their environment variables" do
+    ENV.update("SOLIDERRORS_SEND_EMAILS" => "true", "SOLIDERRORS_EMAIL_FROM" => "env@example.com")
+    SolidErrors.send_emails = false
+    SolidErrors.email_from = "config@example.com"
+
+    assert_equal [false, "config@example.com"], [SolidErrors.send_emails, SolidErrors.email_from]
+  end
+
+  test "email settings keep their defaults when neither is set" do
+    assert_equal [false, "solid_errors@noreply.com", nil, nil],
+      SETTINGS.map { |name| SolidErrors.public_send(name) }
+  end
+end