kmail can't send to group

[Michael Hirsch]

Somehow my kmail has lost the ability to send to a group.  I created a
group in my address book named "parents" with my parents' email
addresses in it.

Then, when I compose a new mail and address it to "parents" I am
unable to send the email.  Kmail puts up an error dialoge saying:
    parents at doggie
The email address you entered is not valid because it does not contain
a '.'. You will not create valid messages if you do not change your
address.

My computer is named "doggie" which is where that must be coming from,
but I would have expected the email to go out to my parents.

My dad is having the same problem, so it is not unique to my machine.
My guess is that I'm missing a configuration option allowing me to
send to groups, but I can't find it.

What am I doing wrong?

Thanks,

Michael