LDAP Sync - find Failed Entrys in Log

Used Zammad version: 3.1
Used Zammad installation source: Package
Operating system: Ubuntu 18.4 LTS

Hello,

i got 20 Entries which are failing in the LDAP Sync. I took a look in the Zammad Production.log and found the following Entries:

E, [2019-12-01T06:35:29.708738 #1107-70210406209900] ERROR – : Email address is already used for other user. (Exceptions::UnprocessableEntity)
/opt/zammad/app/models/user.rb:1049:in `ensure_uniq_email’

Ok the Error is clear, but where i can see which Adress is not unique?

Thank you for your help.