OT: Email address for this group

Hello: I am trying to set the address to receive individual
messages from this group (and others) to my personal email
address, but the Yahoo system gives me an "Invalid address
error". I have already checked the address, answering and
clicking the link, to confirm that it is of my own. What is wrong? It
is an email from a domain from Argentina. So it ends in
".com.ar"... is this the problem? Thanks, regards, Máximo.