mail.app --separate mailboxes

so... before i got this Mac i used a Vista laptop with MS Outlook, which combined mailboxes into one (my personal account is pushed via GetSync'd/Kerio which works great) with the mailboxes combined i consequently also received 2 other accounts on my iPhone w/o setting up the mail addresses i have, which was great. now since mail on the Mac separates the mailboxes this is no longer the case, is there a elegant way to make this happen again ? i kinda like the separate mailboxes but at the same token i like to receive all my mail pushed to my iPhone.

thanks in advance.