si infatti mi arrivano i delivery tipo:

Hi. This is the qmail-send program at mail5.interhost.it.
I'm afraid I wasn't able to deliver your message to the following addresses.
This is a permanent error; I've given up. Sorry it didn't work out.

<email@dominio.it>:
Sorry, no mailbox here by that name. (#5.1.1)


oppure


The following message to <info@dominio.it> was undeliverable.
The reason for the problem:
5.1.0 - Unknown address error 511-'sorry, no mailbox here by that name (#5.1.1 - chkuser)'



vuol dire che gli indirizzi non esistono piu'?