To add to SMH's post....
She's phoned O2 & not got much help? No surprise there. Their CS sucks.
Does she have all the proper connection settings on her phone?
This page will send various connection settings (for GSM WAP, GPRS WAP, & GPRS MMS etc) in an auto-setup SMS:
http://www.o2.co.uk/productsservices...0,,184,00.html
Then, as SMH said, she will need to set up the phone's email client with the correct connection type, & the inbox & outbox details etc.
Also, email may not work through a normal GSM WAP or GPRS WAP connection - the client may need a direct GPRS net connection, rather than one which goes via a WAP gateway. (the O2 settings do provide a normal direct connection - it's called "O2 Mobileweb" on my P900 - as well as GSM & GPRS WAP gateway connections).