Multi-User Mail Sharing for Pervasive Devices
Original Publication Date: 2002-Jun-01
Included in the Prior Art Database: 2003-Jun-21
Disclosed is a method and program that supports the sharing of mail accounts among users of limited storage, pervasive, Internet devices. In the case of devices designed to support multiple users per device, the need has arisen to support both multiple mail accounts and the sharing of mail accounts among multiple users. This gives each user the choice of either owning a unique mail account or sharing one with other users of the device (or any combination). Whereas previous such implementations organized mail files and folders by the userid, this solution employs the name of the mail server and account name in the location (i.e. directory path) of the mail and information. In the interest of preserving the limited local storage on pervasive devices, where possible, mail and related stats are stored on the mail server. Where this is not possible, such as POP3 mail folders, only a single copy is kept on the device, regardless of the number of users sharing a mail account. This solution addresses the family situation (where some family members may choose to share a single mail account), as well as a shared dormitory situation (where each resident would be inclined to have a separate mail account). It also supports a multiple system environment (one for home, one for work or traveling). A preferred embodiment of this invention includes the following features. First of all, since multiple users put an additional burden on a limited storage device, all INBOX mail (Incoming Mailbox) is kept on the server (including POP3 mail servers, which traditionally move mail to the client upon receipt). This keeps incoming mail accessible to multiple users (or multiple devices) until some action is taken (Save or Delete). This solution relies on the use of server storage wherever possible, to limit the strain on local (client) storage that is magnified by the addition of multiple users. In considering additional mail folders (such as "Saved Mail"), an IMAP mail server defines this folder on the server and thereby makes it accessible to all users of the same mail account. However, in the case of POP3, which does not provide the ability to define additional folders on the server, the "Saved Mail" folder must be defined on the local device. Sharing must be achieved by placing the folder in a shared directory path (based on the server address and mail account), available to all users of that shared account. Similarly, the "Read/Unread" status of each mail message can be shared by either keeping it on the server (possible with the IMAP protocol) or by means of a bookkeeping file kept in the aforementioned shared directory per each mail account (necessary in the POP3 case). With this configuration, messages read by one of the sharing users, will be marked "Read" for other users on the same device. This fits well into the limited local storage strategy for Internet devices, by keeping single copies of information in local storage wherever possible.