[Samba] Unknown sender

[support at rsvp.com.au]

RSVP can't send your email, because we don't have any record
of a member with your email address. RSVP can only send
emails from your registered email address.

If you haven't registered at all, please go to
http://www.rsvp.com.au and join our Free Trial to try out
our service.

If you are a member, you may have registered using a
different email address. Please log in to RSVP at
http://www.rsvp.com.au and check your registration details.
If your email address has changed since you registered, you
can update it, and we will send you a confirmation email to
make sure we can contact you at the new email address. Once
you've returned that email to us, you'll be able to send and
receive email again.
                
If you have registered, but haven't confirmed your membership
by returning the email we sent you containing your
confirmation code, you won't be able to send any RSVP email.
If you don't have a copy of that confirmation email, please
contact us at help at rsvp.com.au, and we'll send you another
one.            
                
Thanks from RSVP.
http://www.rsvp.com.au

Sent by RSVP in relation to your account with RSVP. If you believe you have received this email in error, please contact support at rsvp.com.au.