Exim / sending mail from dial-up machine w correct sender address

["Endrey Balint" <balint22@freemail.c3.hu>]

Hello,

I have Slink on my home machine. I used eximconfig to set up exim for a
dialup system using smarthost, and I accepted the default values.

The parameter qualify_domain defaulted to 'mikszath' which is the home-made
name of my machine and is not related to any real domain names. When I tried
to send out a message, the delivery failed:

  balint22@freemail.c3.hu:
    SMTP error from remote mailer after MAIL FROM:
    <balint@mikszath> SIZE=1473:
    host mail.digitel2002.hu [194.9.67.1]:
    501 <balint@mikszath>... invalid host name mikszath, check your
+configuration.

Apparently the ISP's SMTP server required a valid host name.
If I changed qualify_domain to any valid name (e.g. mail.digitel2002.hu),
the
delivery worked but when I checked the header of the delivered message, it
looked like this:

>From balint@mail.digitel2002.hu Sun Jun 13 22:03:06 1999
(...)
From: Balint <balint22@freemail.c3.hu>  (that's what I set up in Mutt)
(...)
Sender: <balint@mail.digitel2002.hu>
(...)

which makes no sense since this address is an invalid combination of my
local username and the specified qualify_domain and I guess this causes
problems when returning some mail.

I also checked how the same message looks like if I send it from Windows
(OE5); it had no Sender: field and the starting From line contained the
same address as in the Form: field, i.e. balint22@freemail.c3.hu

So, my question is how to set up exim (and my mail client?) so that I
could specify those Sender/From/Return-path etc. header fields to
be the address I prefer (balint22@freemail.c3.hu).

Thanks
Balint

P.s. My /etc/exim.conf file:

qualify_domain = mikszath
local_domains = localhost
local_domains_include_host = true
local_domains_include_host_literals = true
never_users = root
host_lookup_nets = 0.0.0.0/0
sender_host_reject_relay = *
trusted_users = mail
smtp_verify = false
gecos_pattern = ^([^,:]*)
gecos_name = $1
received_header_text = "Received: \
          ${if def:sender_fullhost {from ${sender_fullhost} \
          ${if def:sender_ident {(${sender_ident})}}\n\t}\
          {${if def:sender_ident {from ${sender_ident} }}}}\
          by ${primary_hostname} \
          ${if def:received_protocol {with ${received_protocol}}} \
          (Exim ${version_number} #${compile_number} (Debian))\n\t\
          id ${message_id}"
end
local_delivery:
  driver = appendfile
  group = mail
  mode = 0660
  mode_fail_narrower = false
  file = /var/spool/mail/${local_part}
address_pipe:
  driver = pipe
  return_output
address_file:
  driver = appendfile
address_directory:
  driver = appendfile
  no_from_hack
  prefix = ""
  suffix = ""
address_reply:
  driver = autoreply
remote_smtp:
  driver = smtp
end
real_local:
  prefix = real-
  driver = localuser
  transport = local_delivery
system_aliases:
  driver = aliasfile
  file = /etc/aliases
  search_type = lsearch
userforward:
  driver = forwardfile
  no_verify
  check_ancestor
  file = .forward
  modemask = 002
  filter
localuser:
  driver = localuser
  transport = local_delivery
end
smarthost:
  driver = domainlist
  transport = remote_smtp
  route_list = "* mail.digitel2002.hu bydns_a"
end
*                      *           F,2h,15m; G,16h,2h,1.5; F,4d,8h
end