If erlang is installed from source, rpm install of rabbitmq fails to recognize erlang stating that erlang R12B-3 is required.
Use:
rpm --nodeps -Uvh rabbitmq-server-2.6.1-1.noarch.rpm
I was able to install and use RabbitMQ 2.6.1 successfully on CentOS 5.6 with Erlang R14B04