Which version are you refering to? I can only find a version of April 2015. It says nothing about TLS support (except STARTTLS for SMTP). Neither can I find a RSA key length support statement.
(For security reasons we are not allowed to use SSL-v1,-v2,-v3, TLSv1,-v1.1. We are only allowed to use TLSv1.2 with at least 2048 bit RSA keys or ECC keys.)