I created both the SETI account and her email account.  As I own the
domain I created her email account for I *should* be able to get the
addy right.

Do you also control the mail system for the domain? Does it have any
anti-spam filters set up (particulary RBL checkers that might be integrated
into, for example, exim and operate quite 'quietly')? Do you have any other
email accounts on that same domain, that are also used with Seti@home, do
they work?