Configure RSync backup between two Centos machines

I have two machines at two different networks. On machine needs to run a bash script to dump a SQL database (already created and tested). This script needs to be modified remove any old sqldumps. Leaving a few behind encase a backup fails. The other machine needs to rsync to the first pc and copy the SQL file to itself. This is to backup customer data and hence needs to be as secure as possible. A notification email of success/failure would be necessary as well.