[pkg-kolab] Apt install Kolab server Debian unstable

[Geordie]

Good day
I ran into dependencies problems trying to install the Kolab server. My first 
problem was with postfix. Postfix seems not to like exim and requested all exim 
packages be removed. I checked with the maintainers of Gnumed whose server 
package upload exim. This was not a problem as long as there was a mta. So 
exim was removed.
My next issue is with kolab-cyrus-imapd. With a little digging this package 
requires libzephyr3. According to the maintainer of libzephyr, libzephyr3 is 
no longer available in unstable. However libzephyr 4 is available.
I also have a dependency problem with kolab-cyrus-pop3d. I did not check into 
this. 
Any help with this would be greatly appreciated
Geordie