Yes, use the default sieve filters. E.g., new filter, for all incoming mails, action: reply with message.

I made a filter rule in roundcube with:
reply with message ... etc

belive me ... this is a hard job for my users
My vacation plugin works well but it dosen't save e-mail messages to imbox, this is the only problem. I hope i will find a answer

Tx again maxie

i like roundcube filters. i can use it like this, but people from business want separate vacation tab in roundcube settings ...

Thanks!

If anyone wants to install a vacation plugin to set "out of office" from a user friendly interface:

I used freeBSD 8.0 in this tutorial.

1)-------------------------------------------------------------------------------
pw groupadd vacation
pw useradd vacation -c Virtual\ Vacation -d /nonexistent -g vacation -s /sbin/nologin
mkdir /var/spool/vacation
cp /usr/local/www/postfixadmin/VIRTUAL_VACATION/vacation.pl /var/spool/vacation/
chown -R vacation:vacation /var/spool/vacation/
chmod 700 /var/spool/vacation/
chmod 750 /var/spool/vacation/vacation.pl
2)-------------------------------------------------------------------------------
edit /var/spool/vacation/vacation.pl
{
    $db_type = 'mysql';
    $db_host = 'localhost';
    $db_user = 'vmail';
    $db_pass = 'postfix_sql_password';
    $db_name = 'vmail';
    $syslog = 1;
}

MYSQL GRANTS
mysql> SHOW GRANTS FOR vmail@localhost;
+--------------------------------------------------------------------------------------------------------------+
| Grants for vmail@localhost                                                                                   |
+--------------------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'vmail'@'localhost' IDENTIFIED BY PASSWORD 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx' |
| GRANT SELECT ON `vmail`.* TO 'vmail'@'localhost'                                                             |
| GRANT INSERT, DELETE ON `vmail`.`vacation` TO 'vmail'@'localhost'                                            |
| GRANT SELECT ON `vmail`.`mailbox` TO 'vmail'@'localhost'                                                     |
| GRANT SELECT, INSERT, DELETE ON `vmail`.`alias` TO 'vmail'@'localhost'                                       |
| GRANT SELECT, INSERT, DELETE ON `vmail`.`vacation_notification` TO 'vmail'@'localhost'                       |
+--------------------------------------------------------------------------------------------------------------+
3)-------------------------------------------------------------------------------
append /usr/local/etc/postfix/master.cf with
vacation  unix  -       n       n       -       -       pipe
  flags=DRhu user=vacation argv=/var/spool/vacation/vacation.pl -f ${sender} ${recipient}

edit /usr/local/etc/postfix/main.cf
transport_maps = [...] hash:/usr/local/etc/postfix/vacation
vacation_destination_recipient_limit = 1

[replace autoreply.domain.tld]
echo 'autoreply.domain.tld vacation:' >> /usr/local/etc/postfix/vacation
postmap /usr/local/etc/postfix/vacation

postfix reload

4)-------------------------------------------------------------------------------
- get vacation plugin http://github.com/bhuisgen/rc-vacation/
- copy the plugin to /usr/local/www/roundcube/plugins/
- add ,"vacation" into $rcmail_config['plugins'] - /usr/local/www/roundcube/config/main.inc.php

edit /usr/local/www/roundcube/plugins/vacation/config.inc.php and replace $rcmail_config['vacation_sql_write'] and autoreply.domain.ltd with your needs.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`
// write data queries
$rcmail_config['vacation_sql_write'] =
        array("DELETE FROM vacation WHERE email=%email AND " .
                 "domain=%email_domain;",
          "DELETE from vacation_notification WHERE on_vacation=%email;",
          "DELETE FROM alias WHERE address=%email AND " .
                 "domain=%email_domain;",
              "INSERT INTO vacation (email,domain,subject,body,created," .
                 "active) " .
                 "SELECT %email,%email_domain,%vacation_subject," .
                    "%vacation_message,NOW(),1 FROM mailbox " .
                 "WHERE username=%email AND domain=%email_domain AND " .
                    "%vacation_enable=1;",
          "INSERT INTO alias (address,goto,domain,created,modified," .
                 "active) " .
             "SELECT %email,CONCAT(%email_local,'#',%email_domain,'@'," .
                "'autoreply.domain.ltd,',%email_local,'@',%email_domain),%email_domain,NOW(),NOW(),1 " .
             "FROM mailbox WHERE username=%email AND " .
                "domain=%email_domain AND %vacation_enable=1;",
          "INSERT INTO alias (address,goto,domain,created,modified,active) SELECT %email,CONCAT(%email_local,'@',%email_domain),%email_domain,NOW(),NOW(),1 FROM mailbox WHERE username=%email AND domain=%email_domain AND %vacation_enable=0;"
    );

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`

ee /var/spool/vacation/vacation.pl

replace: 'ctype' => 'text/plain; charset=UTF-8',
with: 'ctype' => 'text/html; charset=UTF-8',
on line: 443

make a test

Excuse me, what do you mean 'number of vacation message'?

Currently, you can set how many responses per-day.

edit vacation.pl script
[my location][/usr/local/etc/postfix/vacation.pl]
go to line 152 that looks like this:

# notification interval, in seconds
# set to 0 to notify only once
# e.g. 1 day ...
#my $interval = 60*60*24;
# disabled by default
our $interval = 0;

modify $interval variable value;

It's set in roundcube Filter tab, create a new filter with action 'out of office'.

Ok, but what about if the recipient is an alias? How do I set an autoresponder to an alias?

I didn't wanted to get my hands dirty by modifying anything in the database. At most I would loved a sieve conf variant (like here http://wiki.dovecot.org/LDA/Sieve#Vacat … -reply-1), but for an unknown cause it didn't worked for me.
After googling for a half a day after... nothing and being in a hurry I'v converted the alias in a real account in postfixadmin, setup an autoresponder filter in roundcube for it and another one right after wich redirects the emails to another alias created in postfix.
A little quircky, but worked...