README.md in mailkick-0.1.5 vs README.md in mailkick-0.1.6

@@ -193,10 +193,10 @@
 ## Reference
 
 Change how the user is determined
 
 ```ruby
-Mailkick.user_method = proc {|email| User.where(email: email).first }
+Mailkick.user_method = -> (email) { User.find_by(email: email) }
 ```
 
 Use a different email field
 
 ```ruby