I have sent a Package to a remote DP but it has not arrived. Looking in the replmgr.log on the sending Site it states:
"There are jobs to <target_site_code> of the same priority waiting to be sent, won’t send this batch"
Check that you have created an Address both FROM the Sending Site TO the receiving Site and vice versa. In this case the Address hadn’t been created from the sending Site to the receiving Site. After doing this everything burst into life.