[Dovecot] sieve vacation

[Lampa]

Hello,

scenario:

OK 1. created vacation script (see below)
OK 2. send message from user at anotherdomain.tld to user at domain.tld =>
got auto vacation response (2010-02-11T19:42:13)
OK 3. send message from user at anotherdomain.tld to user at domain.tld =>
no response (is ok because ":days 1" settings) (2010-02-11T19:47:46)
BAD 4. send message from anotheruser at anotherdomain.tld to
user at domain.tld => no response (2010-02-11T19:48:04)


Why is discarding vacation response for message implicitly delivered
to <user at domain.tld> ?

log:
2010-02-11T19:42:13.669321+01:00 hermes dovecot:
deliver(user at domain.tld): sieve:
msgid=<052a01caab49$ec4752e0$c4d5f8a0$@tld>: sent vacation response to
<user at anotherdomain.tld>
2010-02-11T19:42:13.732541+01:00 hermes dovecot:
deliver(user at domain.tld): sieve:
msgid=<052a01caab49$ec4752e0$c4d5f8a0$@tld>: stored mail into mailbox
'INBOX'
2010-02-11T19:47:46.271534+01:00 hermes dovecot:
deliver(user at domain.tld): sieve:
msgid=<053201caab4a$b295ece0$17c1c6a0$@tld>: discarded duplicate
vacation response to <user at anotherdomain.tld>
2010-02-11T19:47:46.275891+01:00 hermes dovecot:
deliver(user at domain.tld): sieve:
msgid=<053201caab4a$b295ece0$17c1c6a0$@tld>: stored mail into mailbox
'INBOX'
2010-02-11T19:48:04.958622+01:00 hermes dovecot:
deliver(user at domain.tld): sieve:
msgid=<053701caab4a$bda90220$38fb0660$@tld>: discarding vacation
response for message implicitly delivered to <user at domain.tld>
2010-02-11T19:48:04.965875+01:00 hermes dovecot:
deliver(user at domain.tld): sieve:
msgid=<053701caab4a$bda90220$38fb0660$@tld>: stored mail into mailbox
'INBOX'

vacation script:
-----------
require "vacation";

vacation
:days 1
:subject "Auto reply"

"auto reply message";
--------------

Thank you
-- 
Lampa