I have a user that can not send or receive e-mail from her two sons
(different locations) while on our system at work but can from home
her ISP. When trying to send them e-mail the mail is bounced back
with the
message "Domain xxxx does not exit" referring to our domain. Is this
problem on my part or their's? Both are on different ISP's. I have
reverse-DNS set up and checked things out through DNSReport which
shows it
to be working for verification.

Any ideas or suggestions on where to start would be appreciated. Why
would just be happening to these two addresses, I'm not sure, unless
haven't got to me yet. Otherwise mail is going out and coming in.

Thank you,