Is it possible that the user existed on the Composr system before the confirmation option was turned off? If this is the case the member account would already have a confirm requirement stored against it.

I believe LDAP users normally can't be confirmed, as they are created without a confirm code.

The only user, which is in the Composr db is admin.

The other features: "Do not take date of birth","Require rule-acceptance upon joining", works ok for LDAP users.

As I understand LDAP user in Composr DB is created only then, when it logs in first time. NOT when LDAP is configured in Composr.

I've reviewed some more and I understand now. The option you're referring to is about those confirmation emails sent out when people join a site, to confirm the email address they entered really is their address.
Composr supports them for members joining via the 'join' module (i.e. the more common scenario in Composr).

Here we have something different. Composr guesses the user's email address from LDAP, and pre-populates the "complete account" form with it. From the point of view of the code it's not a confirmation, it's a pre-population designed to stream-line things.

We can keep this open as a feature request if you like, or you can consider sponsoring, or implementing yourself. We'd need cns_member_external_linker_ask to be bypassed for the case where the form is fully pre-populated, probably by turning on an option to enable this behaviour.

ok, then wait for release, where this is implemented. :)

We'll be moving to having an option to control whether to bring up this screen or not, rather than trying to auto-detect.