mutt/ssmtp From:

[Schoppitsch Dieter <dieter.schoppitsch@uta.at>]

Hi!

I'm running ssmtp (MTA) and mutt (MUA) which works fine for a
'single user dial up'.

Unfortunately the one who receives mail from me is seeing in the
'From:-line' my <linux-username@linux-hostname> and not a
'replyable' email address like <ds@uta4you.at> (which is
'reserved' for/at my ISP.

Dealing with an explicit From:-line (ESC+f) 
or the my_hdr-statement (.muttrc) shows
again <linux-username@linux-hostname> at the receiver or
gives me following messages:

* Error sending message, child exited1 ().
* ssmtp: didn't get initial OK message from smtp server.

Does the ISP refuse 'his reserved' email address?
What can I do/try?

Thanks for any help.
Dieter