340
Apple announced RCS with a whimper when it should have been a bang
(www.theverge.com)
This is a most excellent place for technology news and articles.
RCS was designed to be implemented by the carriers, but all the carriers tried it, failed to gain any traction, and dropped support again, so now the only server is the Google one which is used automatically by the Google messaging app (which, to their credit, does support encryption, through a proprietary extension which they are now allowing Apple to use as well)