Deleting or archiving a message removes it from your inbox. If you delete a message, it's placed in the Trash and then permanently removed from your Google Apps account after 30 days. If you archive a message, it's moved to All Mail (your archive), where you can easily find it in the future, using Google's powerful search feature. Since you have plenty of space for storing all your mail (25 Gb), we recommend that you archive messages rather than permanently deleting them.