Grazie della attenzione,
però il problema si manifesta con Outlook 365, che mostra nella posizione del mittente il
Sender, mentre se uso Windows Live Mail, ad esempio, la stessa mail apppare con il mittente corretto di
From, quindi si direbbe più un problema di rappresentazione di Outlook che del mittente. E corretta anche la visualizzazione mittente ad esempio sullo smartphone.
Outlook 365:

Windows Live Mail:

Di seguito ecco le proprietà della e-mail:
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Date: Mon, 27 Feb 2017 09:36:02 +0100
To: "@studioperigeo.it" <@studioperigeo.it>
From: Newsletter PcProfessionale <*****@pcprofessionale.eu>*
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E così similarmente per tutte le condizioni di intermediario di Sender.
Grazie, saluti
Roberto P.