What I am trying to do is, sending an email to one person but I want to add more email addresses in the TO field and don't want that users to get the email. Is it possible to somehow configure this?
Yes, this is completely possible. SMTP doesn't actually use the headers for anything; the envelope recipient list controls who actually receives a message (though many user-visible email programs will simply copy the To:
, Cc:
, and Bcc:
headers into the envelope on submission).
Because you are not asking about any particular language, I won't post code which probably won't be useful to you anyway. In pseudocode, something like
s = smtp.connect(server)
s.ehlo()
s.from(envelope.sender)
for r in envelope.recipients:
s.rcpt(r)
s.data('''From: me@example.net
To: you@example.org
Subject: SMTP doesn't care
By the time SMTP transmits the actual message,
the recipient information has already been sent
separately.''')