If you are going on vacation and you need to set up a Vacation Auto Reply on your business Exchange email account, and you need to do this from your iPhone, this is a vary simple task.
Here’s how it’s done.
First, open your Settings app on your iPhone and click on the Mail, Contacts, Calendars button
Next, click on your Exchange button.
Once you have opened you Exchange, you will need to click on the Automatic Reply button.
Once you have opened the Automatic Replay, you will need to fill out the Away Message and turn the Automatic Reply message on.
Congratulations! You did it! Have a great, stress free vacation!