Currently the http client supports Basic, Digest and NTLM authentication out of the box, however there's no way to explicitly specify what kind of authentication method to use. Rather the version used is based on whether you pass a username/password or a username/password and domain. We should have an authMethod option for the URI that allows a user to explicitly set what kind of authentication method to use, or a combination of authentication methods to try, something like:

to("http://somehost?authMethod=BASIC");

or:

to("http://someotherhost?authMethod=NTLM,BASIC");