It should be differentiated between the different wireless devices, due to the different possibilities they offer and can support.

Since beginning of the year 2000, the Wireless Application Protocol (WAP) has been implemented by Austria GSM Operators, which allows a mobile subscriber with a WAP enabled handset to access and use contents and applications that are written for WAP, i.e. written in wireless markup language (WML). In this case, the operator implements a email client (either self-written or subcontracted, e.g. One's Wap email client was written by Web Dynamite, or an "of the shelf" solution is implemented like Telering's email client was implemented by MATERNA. The email clients in these examples do exactly that what an outlook express or pine do, which is access a POP or IMAP email system and extract the emails from it. Therefore these WAP email clients are said to be competing products to a Pine or Outlook Express, however set up for the wireless devices (handsets) rather than Pine or Outlook Express in our case which are designed for the wireline fixed desktop pc devices.

It was not possible during the course of this research, to discover modules that the creators of Pine or Microsoft for Outlook Express has developed, that are WAP email clients, nor clients that can share or integrate the email clients with WAP email clients of some kind.

Microsoft offers for the pocket pc product range (e.g. Compaq iPAQ) in addition to almost all of its software compact edition, an outlook express email client, which is compact edition. It is downloadable from the MS website or available on the installation CD of the Pocket PC, and is installable on the pocket pc via the connection to the pc on which the installation CD is run.

The email client in this case, can in combination with a GSM phone (for data dial-up calls) access IMAP and POP3 accounts. Microsoft also offers on that product range, a client that can read and transfer emails received on the desktop outlook express, to the pocket pc by using the Microsoft synchronizing software called ActiveSync.

It was not possible to find a Pocket PC or Palm or Personal Digital Assistant email client from Pine. This however does not mean it does not exist, as power users always write themselves programs, which would enable a Pine email client to be set up on a pocket pc. This case was what happens with the Linux based products, as power users of Linux write themselves the programs that are required for their different devices.