04-12-2013 10:19 PM - edited 04-12-2013 10:20 PM
Touch and hold an email, slide your finger onto the menu that pops up on the right side of your screen, and then slide down onto the checkbox icon, then slide slightly left and when the word select more pops out, release your finger. This will eventually become a smooth easy reflexive motion.
Then simply select the emails you want to file and then tap the file folder icon that is on the right side of your screen.
The only caveat is that you can not file across different accounts (you cannot file from email account A's inbox into email account B's file folders) and if you select emails from different accounts that file icon will disappear.
To be sure you are selecting from the same account, choose the tab for only that account.