If you’re like me, you probably used Gmail for a while and let the inbox grow and grow until you have tens of thousands of emails over the last few years. Truth is…you’re supposed to archive old emails. Archiving old emails makes it easier for you to set up Imap-based applications like Apple Mail — it will attempt to download everything in your inbox. If your inbox is too full, it takes ages to download all your old mail. The best way is to archive old mail.
So…
How to Archive Old Mail in GMail
Load up GMail (or Google Apps GMail).
Click on “Settings”
Click on “Filters”
Create a new Filter
In the “Has the words:” field, add “before:2010/05/01″ (change the date to whatever date you want. Format: YYYY/MM/DD).
Click on “Next Step”
Check the box “Skip the Inbox (Archive it).
Check the box “Also apply to {number} conversations below.”
Create or Update the filter.
And voila, your inbox is now clean. 
