some one please explain what IMAP support means.. every time someone mentions outlook they mention lack of IMAP as its disadvantage. and also why it is such an important feature?
Consider IMAP as being the cloud email service. All the emails are pulled on your device/web/client whenever you want or whenever they arrive. Its like the standard protocol for all possible clients/interfaces to pull the mails for you.
Soon after IMAP was created, Microsoft introduced its own protocol called MAPI ( Messaging Application Programming Interface ) which practically is IMAP for hotmail/outlook. MAPI is now commonly known as Exchange as it runs on their Exchange Servers.
Practically all email services ( apart from outlook/hotmail) support IMAP now as its accepted almost everywhere and used on all web/device/clients.
As Exchange/MAPI are Microsoft products, only companies that have their own Exchange mail servers or use Windows Live Hotmail/Outlook servers will be able to use MAPI/Exchange.
(I use IMAP nevertheless since Exchange/MAPI has some annoying issues on iOS if used with Gmail and Exchange/MAP is not supported by Mail.app on OS X.)
Having IMAP is worth it...
The more basic approach 'POP' downloads a copy, no syncing.