diff --git a/lib/mailgun_rails/deliverer.rb b/lib/mailgun_rails/deliverer.rb
index ddf073c..736a63f 100644
--- a/lib/mailgun_rails/deliverer.rb
+++ b/lib/mailgun_rails/deliverer.rb
@@ -21,7 +21,13 @@ def verify_ssl
     end
 
     def deliver!(rails_message)
-      response = mailgun_client.send_message build_mailgun_message_for(rails_message)
+      begin
+        response = mailgun_client.send_message build_mailgun_message_for(rails_message)
+      rescue RestClient::Exception => mailgun_error
+        json = JSON.parse(mailgun_error.http_body.to_s) rescue raise(mailgun_error)
+        mailgun_error.define_singleton_method(:message) { json["message"] }
+        raise mailgun_error
+      end
       if response.code == 200
         mailgun_message_id = JSON.parse(response.to_str)["id"]
         rails_message.message_id = mailgun_message_id
diff --git a/spec/lib/mailgun_rails/deliverer_spec.rb b/spec/lib/mailgun_rails/deliverer_spec.rb
index 892469f..f617f79 100644
--- a/spec/lib/mailgun_rails/deliverer_spec.rb
+++ b/spec/lib/mailgun_rails/deliverer_spec.rb
@@ -115,12 +115,30 @@
       msg.message_id.should eq "20111114174239.25659.5817@samples.mailgun.org"
     end
 
+    it "should include the error message returned from Mailgun in the Ruby exception message" do
+      msg = Mail::Message.new(to: [], cc: 'cc@email.com', from: 'from@email.com')
+      expectation = { to: [], cc: ['cc@email.com'], from: ['from@email.com']}
+      check_mailgun_error msg, expectation, RestClient::BadRequest, "'to' parameter is missing"
+    end
+
     def check_mailgun_message(rails_message, mailgun_message)
       rest_response = double(:code => 200, :to_str => '{"message": "Queued. Thank you.","id": "<20111114174239.25659.5817@samples.mailgun.org>"}')
       mailgun_client.should_receive(:send_message).with(mailgun_message).and_return(rest_response)
       MailgunRails::Deliverer.new(api_key: api_key, domain: domain).deliver!(rails_message)
     end
 
+    def check_mailgun_error(rails_message, mailgun_message, exception, message)
+      body = %{{"message": #{JSON.dump message}}}
+      response = double(code: 400, body: body)
+      exception = exception.new(response)
+      allow(mailgun_client).to receive(:send_message).and_raise(exception)
+      expect {
+        MailgunRails::Deliverer.new(api_key: api_key, domain: domain).deliver!(rails_message)
+      }.to raise_exception(RestClient::BadRequest) {|exception|
+        expect(exception.message).to eq message
+      }
+    end
+
     def rails_message_with_attachment
       msg = basic_multipart_rails_message
       msg.attachments["attachment.jpg"] = "\312\213\254\232"