mailto formula not working

Hi,

I have a table with a list of contacts.  One of the columns is the e-mail address (column is called EmailAddress1).  So I would like to add a button to e-mail the highlighted contact.  I've added the button with a system action of hyperlink.

The hyperlink address is "mailto:@EmailAddress1"

When clicking the button though, it launches outlook, but puts @EmailAddress1 in the to field.  Any idea where I'm going wrong?

Thanks

Paul