[imp] problem with virtual hosting using horde

[Andy]

REDHAT 7.3
QMAIL-1.03
HORDE-2.1
IMP-3.1
Apache-1.3.22

My mail server needs to host 3 domains domains, maxxbioscience.com,
maxxbiotech.com, maxxcapital.com

I have set up qmail to do it successfully, then I set up horde for
maxxbioscience.com andeverything 's fine as well. However, problems come out
when I try to set up horde for maxxbiotech.com.

In my httpd.conf, I have:

NameVirtualHost mail.maxxbioscience.com
Alias /horde /usr/local/apache/htdocs/maxxbioscience/horde/
Alias /horde/ /usr/local/apache/htdocs/maxxbioscience/horde/


<VirtualHost mail.maxxbioscience.com>
    ServerAdmin andy at maxxbioscience.com
    DocumentRoot /usr/local/apache/htdocs/maxxbioscience/horde/imp
    ServerName mail.maxxbioscience.com
    ErrorLog logs/mail_maxxbioscience_errorlog
    CustomLog logs/mail_maxxbioscience.com_access_log combined
</VirtualHost>

NameVirtualHost mail.maxxbiotech.com
Alias /horde /usr/local/apache/htdocs/maxxbiotech/horde/
Alias /horde/ /usr/local/apache/htdocs/maxxbiotech/horde/


<VirtualHost mail.maxxbiotech.com>
    ServerAdmin andy at maxxbiotech.com
    DocumentRoot /usr/local/apache/htdocs/maxxbiotech/horde/imp
    ServerName mail.maxxbiotech.com
    ErrorLog logs/mail_maxxbiotech_errorlog
    CustomLog logs/mail_maxxbiotech.com_access_log combined
</VirtualHost>

However, when I try mail.maxxbiotech.com. it will also go to the horde of
mail.maxxbioscience.com. I notice that it is the Alias problem in the
httpd.conf, is there any solution to overcome this as different users belong
to different domains and they cannot be mixed.

Thanks very much for help!

Andy