Create an account with external authorisation

[paulz1]

We use an external authorization for our zimbra.

So, usually for create account of such type directly on zimbra server we use the command :

zmprov ca [e-mail] ""

The second parameter for password is empty.

When I try to use the same principle using zimbra-api it seems that it does not work.
While I saw in the comments in the code :

/**
 * Create account.
 * Notes:
 *   1. accounts without passwords can't be logged into.

For the moment I just can not create an account with empty password at all.
Is it normal?