Arduino Wifi shield

I wanted to know how to send text from arduino to e-mail using wifi shield??

Connect 'client' to Simple Mail Transport Protocol (SMTP) server. Send headers to address the recipient. Send extra linefeed. Send text of the message. Close connection.

Read about the SMTP protocol to learn the headers.

You may have some trouble finding an SMTP server you can use. Because of spammers using email servers they generally require a login.