As you surely know, mail-addresses are made as name@domain (i.e. [email protected]). Mail programs are basically made to receive mails only when addresses matches completely user's account address. Nevertheless, sometimes, the mail program may receive emails even if the name (the string before "@") does not match entirely, based only on the specified domain name of the mail address (the string of characters after "@")
I strongly believe that this is the case of your phrase. I would translate it as following: "When receiving (mails) only based on the domain name indicated in the address, i.e. because of mistaken addresses"