SCALIX-ing

$TOMCAT_HOME/bin/setclasspath.sh

-Djava.net.preferIPv4Stack=true

PATH=$PATH:/opt/scalix/bin:
export PATH

What is the HOSTNAME= value set to in /opt/scalix/global/config? If it is just the host name try changing it to the fqdn. Restart tomcat.
less /opt/scalix/global/config

Hi. One other thing, the reason mail is piling up in /var/spool/mqueue (I'm assuming you meant mqueue rather than mail) is because you don't have your domain/server in the /etc/mail/local-host-names file. Update that file, then restart sendmail and those messages will bounce.

???
vi /etc/mail/sendmail.cf
Djfullyquilifieddomain.

It used to be the case that MaxMessageSize in /etc/mail/sendmail.cf was set to 10M but, looking at my file, this is commented out and the default is 0, i.e. unlimited.

START ALL
omon -s all

1005 vi /etc/mail/local-host-names
1006 omsendin

vi ~scalix/sys/general.cfg

# exactly -- but if they are a little bit late, the server drops their
# connection. Setting a timeout of 31 minutes avoids this problem.
IMAP_IDLE_TIMEOUT=599