Ok so we are deploying SOGo to a new customer with over 1500 users in an existing AD and they are migrating away from Exchange 2003. We created have a nice migration mechanism which allows us to have the SOGo box inside AD as an "Exchange Server" and we can even follow the Microsoft documentation for migrating from one exchange server to another (changing mailbox destination in AD for users/groups). This is great because we can run both servers at the same time and migrate users/groups in batches.
Problem: Openchange build on the SOGo ZEG has samba bugs due to it being based on an earlier samba4 build which led to AD replication issues down the line and in turn led to authentication problem across the entire AD. Also the Zentyal distro provides a nice platform to run SOGo but we found bugs in this too which stopped us using it (we did not even get it working out of the box so we decided not to spend too much time on it since ZEG works out of the box).
The solution was to use the SOGo 2.1.1 ZEG, and rebuild OpenChange with samba 4.1.5. Now it works nicely, no AD sync issues so far and now we can focus on adding neat features to SOGo.
sudo apt-get install build-essential autoconf ccache pkg-config python python-dev git flex bison docbook-xsl xsltproc libpopt-dev libical-dev libsqlite3-dev libmagic-dev libboost-thread-dev zlib1g-dev libparse-pidl-perl libgnutls-dev
cd /usr/src
git clone class="tabDetailViewDFLink" href="//git.openchange.org/openchange.git" target="_new">git://git.openchange.org/openchange.git
cd openchange
wget class="tabDetailViewDFLink" href="http://ftp.samba.org/pub/samba/stable/samba-4.1.5.tar.gz" target="_new">http://ftp.saba.org/pub/samba/stable/samba-4.1.5.tar.gz
tar zxvf samba-4.1.5.tar.gz
mv samba-4.1.5 samba4
#THEN BUILD SAMBA
vim script/samba4_ver.sh and change to 4.1.5
./script/installsamba4.sh packages
./script/installsamba4.sh compile
./script/installsamba4.sh install
#THEN BUILD OPENCHANGE
./autogen.sh && ./configure --prefix=/usr/local
make && make install
ldconfig