eCart5 + UnivEmail, after checkout scss, not all the e-mail in label "TO" receive msg

In this actual eComm the order list is sent via e-mail (with Mail() object). It seems work fine (a part another problem I opened a thread). It arrives at checkout_success.php.

But immediately after I notice that the "FROM" (UE label) e-mail addresses and not all the "TO" (UE label) e-mail addresses didn't receive the order list.

In the list of "TO" email addresses only the second and the fourth receive the e-mails.
I thought to the server, infact the two e-mail have the same provider, but the first too.

Probably it is child of the same problem, but the e-mail arrived not always have the number of "Order Number", it is nearly always empty.

I have attached the files.

Thanks to all