Excel 2007 : Search specific text in a string

Hi,
I have 25K customer records consisting email address,Fname,Lname etc. I want to filter those email addresses having say wxy.com in their email address. I applied the following formula but did not work correctly.

=if(find("wxy.",A1),"Found","Not Found")

This code will filter the results:
wxy@abc.com
wexy@aol.com
john@wxy.co.uk