I have also been interested in "how" this can be done. We started with a previous ZEG built on Ubuntu 11.04 and SOGo 1.3.10 Since we had little experience in Linux configuration (specifically, 'ldap' and 'postfix'), we paid Inverse to complete the configuration.
IF I understand correctly, SOGo is capable of multi-domain configuration, so it may be as simple as creating a secondary domain (not a child domain) alongside (and then removing) 'example.com' Adding SOGoMailDomain to GNUstepDefaults (pg. 14-16) The 'fly in the ointment' is likely to be 'ldap' and Samba4 You will have to create your domain in those services first (or concurrently) before creating the mail domain in SOGo You will also have to create users and mailboxes in 'cyrus' (not difficult) We created Linux users first, but it's not necessary. I am faced now with adding Samba4 It's not a necessity for us but an enhancement. I would think someone with a bit of experience with 'ldap' and 'samba' could do the work. -- [email protected] https://inverse.ca/sogo/lists
