'arno' is the system user as i was logged in and its origin address
'arno@???' was rewritten correctly to full.name@domain
for exim i found the option -F to replace that "arno,,,"
and for mailx there is an option -r xxx that leads to 'xxx
<correct-sender-address>' if xxx is a complete address (i.e.
'correct-sender-address <correct-sender-address>') ,
'xxx@??? <correct-sender-address>' otherwise.
