Multiple Users with the same name

[Mike G]

Hello, 

how can I do the following in Kolab?
I have 2 users with the same name, one for example working in Accounting, the other one in R&D

User 1:
Full Name: John Doe
email: j.doe at example.com

User 2:
Full Name: John Doe
email:john.doe at example.com

So far Kolab does not let me create a second User "John Doe", looks like first name, lastname has to be a unique combination.
Thanks in advance

Mike