Creating an autoresponder through Webmail
This is the easiest method. Start by logging into your webmail. Remember, you can log into webmail by visiting http://yourdomain.com/webmail (replace yourdomain with the website / subscription domain name). Also be sure to use the full email address as the username and the password associated with the email account you are logging into. So, if you want to forward for susie@yourdomain...login as susie@yourdomain...
Now, verify you are logged into the correct email address in the upper right and click "Autoresponders"
This screen will list your current autoresponders for editing as well as give a button to add an autoresponder. Click the "Add Autoresponder" button.
Fill out the from and click the create button. Note that you can choose to set custom start and stop times for your autoresponder in case you need to plan ahead.