The M600i represents a watershed; the transition of UIQ and Symbian OS from flagship to, if not quite mainstay, certainly a pivotal position in Sony Ericsson's range of phones. Differentiation is what the M600i is about; this is not a "do-it-all" device - although there is not too much it cannot do - the M600i is a device with a clear purpose in life and that purpose is messaging.

Sony Ericsson has not gone overboard in styling the M600i. A simple business like rectangular design with, excluding its QUERTY keyboard, a minimum of buttons. On the left of the M600i is a jog dial selector and back button, the top side houses the infrared port and power switch, the right side has a configurable shortcut button and the diminutive Memory Stick Micro slot, and on the bottom is the connection port for power, USB and headset.

As messaging is the M600i's focus it is equipped with a QUERTY style keyboard. This keyboard contains three rows of rocker keys that provide up to four letters, symbols or actions when used in conjunction with the ALT key. The ALT key itself is one of five single function keys on the forth row of the keyboard, which includes a shift key, left and right direction keys and a space bar. The rocker keys are concaved, allowing the left and right sides to be easily selected, by even the largest of thumbs.

The keyboard is certainly functional for day to day use. Commonly used punctuation and messaging symbols are on the keyboard. In addition, the comma and full stop buttons provide a scrolling list to access less commonly used symbols, such as those for currency, mathematical symbols, and braces. Similar functionality provides access to extended alphabetic characters under the letter keys.

If the required symbol is not on these scrolling lists then a more comprehensive list of symbols is available from the menu.

In addition to the physical keyboard the M600i retains UIQ's pop-up on-screen keyboard and handwriting recognition text entry, although it is difficult to imagine these will get much use on the M600i.

Supporting text entry is Zi Corporation's predictive text engine. This provides both word and next word prediction. The "best" prediction is provided in-line with the text being entered, while alternative options are provided in a scrolling display just below the UIQ status bar. "Alternative" predictions are selected with the scroll buttons on the keyboard and a predicted word selected with the return button. Once a word has been typed or a prediction selected the system also predicts the most likely word to follow it.

The prediction is intuitive reacting to the user's most commonly used words, not just a the most likely word based on general usage. If "include" was the last word starting "inc" to be typed the next time "inc" is entered the main (in-line) prediction returns as "include". If the word "increase" was actually wanted it can be selected from the prediction list. The next time "inc" is types the first prediction is "increase", and so on.

The system also remembers words that are not in its built in dictionary and words can be explicitly added to a "My Words". In addition there is the option to select two language dictionaries, which adds similarly spelt words to the prediction list.

This prediction system works well. However, the presentation of the pick list at the top of the screen means its use requires a switching of the point of attention. Positioning the list at the text insertion point would be an improvement.

UIQ has always had a strong messaging application, which is just as well as it remains largely unchanged, at least functionally, on the M600i. There have however been changes in the application's layout and interaction that make it easier to use.

Messaging now provides a shortcut to dial the user's voice mailbox, making the application more of a unified messaging center. Creation of new messages has been simplified with a single "Create New Message" option that provides the ability to create a new message for SMS, MMS, or any of the email accounts, eliminating the need to open an email account first.

Non-email messages - SMS, MMS, beamed files and alike - are now handled through a single "Messages" mailbox.

Underneath each mailbox name a scrollable display provides summary information and click through access to the Inbox, Sent, Drafts and any other standard or created folders.

In addition to cellular messages Messaging allows mail to be collected from Internet email accounts that use either the POP3 or IMAP standards.

The IMAP configuration supports IMAP Idle, allowing push email support. However, for those with POP3 accounts it is possible to create mail download schedules, either for specific periods between two times or for three specific times during a day. These schedules allow the illusion of push email to be created for standard POP accounts.

Email downloads can be restricted to headers only or emails below a specific size, as can the number of emails downloaded in one session.

While Internet based email will be of most interest to consumer users, for the enterprise the M600i is supported by a range of push email solutions. This includes support for push email from Exchange Server 2003 using software supplied by DataViz, which is available as a free download on Sony Ericsson's web site - as it was not obviously preloaded on the device.

One of the issues with messaging, particularly for the business user, is attachment support. To cope with this Sony Ericsson has included QuickOffice and PDF+ to enable viewing (and the case of QuickOffice editing) of the most common email attachments.

QuickOffice does not provide the direct access to Microsoft-files-in-messages feature found on earlier UIQ implementations. This means an attached file has to be opened for viewing, from the mail message, and then saved before it can be edited.

Curiously the Save As function does not appear to automatically pick up the file name, meaning it has to be entered manually, which is a slight inconvenience.

While the messaging capabilities of the M600i are comprehensive there do appear to be two curious omissions. There is no ZIP application. Should a sender think they are doing the recipient a favor by zipping a large attachment, to save on data traffic, it is a false economy as the file cannot be opened. The second omission is that the Shortcut button - even though it is marked with an @, which suggests email to us - is unable to be configured to open the messaging account.

Overall the Sony Ericsson M600i works well as a messaging device. The built-in keyboard is functional and easy to use. The predictive text mechanism works well in speed up text entry. UIQ's messaging application provides more than enough capability for Internet email users. For the enterprise there is support for Microsoft Exchange and Sony Ericsson supports other solutions for alternative mail servers. QuickOffice and PDF+ means that common attachments can be viewed and in the case of Word and Excel files saved for editing.

There is however a lot more to the M600 than messaging, which we start exploring in our second review which takes a closer look at the UI.

For information on developing for the Sony Ericsson M600 visit www.sonyericsson.com/developer/symbian for development information on Symbian OS and UIQ for Sony Ericsson's phones. Full developer specifications for the M600 can be found at http://developer.sonyericsson.com/site/global/products/phonegallery/m600/p_m600.jsp.