Parallel processing of mailboxes. When there are multiple mailboxes registered, a user can choose to check his/her e-mails individually or collectively. There is an "Check Mails" button on each tab page of an e-mail account. When this button is pressed, only the corresponding messages of that that account who do not have a local copy will be downloaded. There is also a "Check All Sites" button on top. Pressing this button, the system will check each account in parallel, making full use of the multi-core and broadband capabilities that comes with popular computing devices of today.