README.md in tuktuk-0.5.4 vs README.md in tuktuk-0.6.0

@@ -37,10 +37,12 @@
 else
   puts 'Email delivered!'
 end
 ```
 
+You can also call `Tuktuk.deliver!` (with a trailing `!`), in which case it will automatically raise an exception if the response was either a HardBounce or SoftBounce. This is useful when running in the background via Resque or Sidekiq, because it makes you aware of which emails are not getting through, and you can requeue those jobs to have them redelivered.
+
 Delivering multiple
 -------------------
 
 With Tuktuk, you can also deliver multiple messages at once. Depending on the `max_workers` config parameter, Tuktuk will either connect sequentially to the target domain's MX servers, or do it in parallel by spawning threads. 
 
@@ -83,10 +85,10 @@
 message = { ... }
 
 response, email = Tuktuk.deliver(message)
 ```
 
-For DKIM to work, you need to set up some TXT records in your domain's DNS. You can use [this tool](http://www.socketlabs.com/domainkey-dkim-generation-wizard/) to generate the key. You should also create [SPF records](http://www.spfwizard.net/) if you haven't.
+For DKIM to work, you need to set up some TXT records in your domain's DNS. You can use [this tool](http://www.socketlabs.com/domainkey-dkim-generation-wizard/) to generate the key. You should also create [SPF records](http://www.spfwizard.net/) if you haven't. Then use [this tool](https://www.mail-tester.com/spf-dkim-check) to verify that they're both correctly in place.
 
 All available options, with their defaults:
 
 ``` ruby
 Tuktuk.options = {