Google announced that they have expanded the options for offline gmail to allow more control of how much e-mail is accessible when off-line.  This is a nice feature that lets the user control by label either all, a length of time (between 4 days to 5 years), or none.  Remember, inbox is nothing more than a label into your mail.  By default the label inbox and starred is set to all. Custom labels are set to 2 months.  Labels such as trash and spam are set to none.  Making the default look like: