[exim] Vacation

I'm sorry guys, but I search for several hours on the Net about a
working vacation setup to work with Exim 4, and it seems I still have a
problem.
I'm using the following transport:
--- cut here ---
# This transport is used for vacation messages if a '.vacation.msg'
exists
uservacation_transport:
debug_print = "T: vacation autoreply for $local_part@$domain"
driver = pipe
command = /usr/bin/vacation $local_part
--- cut here ---

and the following router:

--- cut here ---
# This router delivers a "vacation" message if a file called
'.vacation.msg'
# exists in the home directory.
uservacation:
  debug_print = "R: uservacation for $local_part@$domain"
  driver = accept
  domains = +local_domains
  check_local_user
  # user to put away message in a file called .vacation.msg
  require_files = ${home}/.vacation.msg
  # do not reply to errors or lists or with ADV in the subject
  condition =  ${if or { \
                {match {$h_precedence:} {(?i)junk|bulk|list}} \
                {eq {$sender_address} {}} \
                {match {$h_subject:} {(ADV|Adv)}} \
                } {no} {yes}}
  # do not reply to errors or bounces or lists
  senders = ! ^.*-request@.*:\
            ! ^bounce-.*@.*:\
            ! ^.*-bounce@.*:\
            ! ^owner-.*@.*:\
            ! ^postmaster@.*:\
            ! ^webmaster@.*:\
            ! ^listmaster@.*:\
            ! ^mailer-daemon@.*:\
            ! ^root@.*
  transport = uservacation_transport
  no_verify
  no_expn
--- cut here ---

I get the right answer to an email sent to it the first time, then no
more (I guess I would need to wait for 1 week before the next one). But
the e-mail never gets to the inbox, nor the first time, nor the
following.

Can somebody here help me to fix it, or propose a better solution?

Many thanks