The C903's user interface is a conventionally structured set-up. The main menu uses an icon based grid of a dozen options, with subsequent sub-menus comprising lists of further options, or a few tabbed lists, in a regular mobile phone way. It's an intuitive and straightforward system to negotiate.
The messaging set up is regular Sony Ericsson mid-range, too, with a Conversations option for viewing threads of messages to and from individual contacts, as well as the usual in-box.
In predictive text mode, the phone sometimes tries to guess the next word you'll be typing, based on previous text efforts, and you can easily add or delete words to the phone's text dictionary. The user interface allows you to send text messages or 'upgrade' to MMS messages by adding photos, video etc., simply by clicking on icons at the bottom of the screen
An email wizard helps with setting up your normal POP3/IMAP4 email accounts for either web-based or ISP accounts; once you've input basic account, password and username details the phone automatically checks for and downloads correct settings.
It's a reasonable mid-range phone set up that's straightforward to operate, and push email is supported among the settings options. Attachments can be handled too; you can view documents sent to you, and attach your own content to send to others via email.
Instant messaging is also available, if allowed by your mobile network operator.