How do I authorize a Lync client without a certificate?

Question

Lync

Good time!
When authorizing the client, the error "error checking the certificate from the server" is issued.
There are no problems with clients whose machines are included in the domain.
The CA is in a domain (not public)
How do I authorize a lync mobile client that is not in a domain without a certificate? so that certificates are not used at all when authorizing the client? - I understand not the most recommended solution, however ...
PS
Client authorization - of course, according to the credentials of a user present in AD of the form [email protected]

Answer 1

As far as I know, no way. Well, that is, the link does not know how to connect without ssl. The simplest solution is to send the client, along with the access details (you pass them somehow anyway), the public key from the server\certificate authority.
Well, or buy a normal ssl certificate (maybe there are cheap / free options) added to the trusted ones by default.