diff --git a/README.md b/README.md
index 5609c6b..a963976 100644
--- a/README.md
+++ b/README.md
@@ -63,6 +63,18 @@ You can do this in an [Apache htaccess file](http://php.net/manual/en/configurat
 
 If you've installed via RVM this probably won't work unless you've manually added your RVM bin paths to your system environment's PATH. In that case, run `which catchmail` and put that path into the `sendmail_path` directive above instead of `/usr/bin/env catchmail`.
 
+Don't forget to set 'From' header.
+
+Code example:
+~~~
+<?php
+$to = 'to@domain.tld';
+$subject = 'Subject';
+$message = 'Message';
+$headers = 'From: from@domain.tld';
+mail($to, $subject, $message, $headers);
+~~~
+
 ### Django
 
 For use in Django, simply add the following configuration to your projects' settings.py