0. backup transport files if any
1. stop zimbra
1a. check if every process is really stopped. don’t want to see stalled mysql or something – happened to me once
2. tar zimbra installation folder
3. tar /var/lib/rpm !!! (I forget often to do this)
4. START ZIMBRA!!! (else upgrade could fail)
5. upgrade
6. if everything works, delete backups, else untar and try again
7. restore transport files if any, eg:
a. su – zimbra
b. cp /test/transportfile /opt/zimbra/postfix/conf
c. postmap /opt/zimbra/postfix/conf/transportfile
