Message Service). There are two main problems with this service: first, the
typical email user receives a large number of spam messages in his or her
mailbox; second, not all messages are so urgent as to require a message on
the GSM phone. Consequently a mechanism to notify only the selected
emails is required.
The UbiMail system must essentially provide nomadic access to the email of
its users by supporting several communication channels and media.
The basic functions of the UbiMail system are summarized in the use case
diagram presented in Figure 16.1.
UbiMail must present a compact list of mail present on the mail server. On
demand the user can access the full email contents. In particular the two
main access channels are:
the web browser (HTML); and
WAP devices (WML).
In addition the system must periodically check the mail server and notify
the user when new messages have arrived. This notification consists of an
SMS message sent to the user's GSM mobile phone. It must be possible to
filter the messages for which a notification is required to avoid a flood of
The system must be configurable and allow setting of the user preferences
and the mail server parameters. All the information about a user forms the
Figure 16.1 UbiMail main use cases