So I have been adding users to Zimbra via a modified zmexternaldrisync w/o issue for years now.
However i wish to future proof this methodology as it works in 5.X, but unsure if it will work in 8.X as I have been planning and testing the upgrade path.
I have yet to test zmexternaldirsync but all it does is;
Sync my OpanLDAP users with Zimbra.
Create an alias of firstname.lastname@domain
Add new users to an all@domain distribution list.
Create a generic default password and force them to change it upon first log in.
The script may continue to just work but I always have this worry in the back of my mind.
If I can simply use the default zmexternaldirsync script w/o my mods, I would be happy.
I can list my mods (its Perl) if you wish to look at them.