ActiveSync not displaying all emails

I have several email accounts setup on my android phone using activesync connection but it won't display old emails (only those that have arrived since I configured my mail client). I desperately need to have access to all of my emails (I have removed the limit in the email client so there is no issue on the client side) - is there any way to allow all emails to be synced to the device, regardless of age as I much prefer being able to use activesync rather than having to switch back to imap?