[Dovecot] Sieve problem: No vacation message when mail is addressed to an alias of the mailbox.

[M. Bobkiewicz]

Hi,
I?m facing here a wierd problem: We have a vacation messaging system 
using sieve. When activated the system forwards incomming messages to a 
given address and sents an out of office reply to the sender. This works 
like a charm when the mail is addressed to mailbox at domain. When the 
incomming mail ist addressed to alias.to.mailbox at domain the mail is 
delivered to the mailbox, it is forwarded to the given reciepient but 
there is no auto reply going out to the sender!
Our setup: CentOS 5.2 + postfix 2.5.6 + dovecot 1.1.11 with domain and 
accounts stored in a mysql database.
The script:

require ["fileinto", "vacation"];
redirect "mailbox2 at domain";
keep;
vacation
         :days 1
         :subject "Out of Office reply"
"
The auto reply text.

";

Any advice is welcome,

Best regards,

  Mike