If you have added the correct sender accounts in our hirarchy and you still can’t get the replication to work between sites? Public keys can make a mess when site servers try to communicate between forests since they do not share the same AD objects but I have found a solution!
1. Use “preinst.exe” to fix this problem.
2. Export the keys in both child and parent.
3. Copy the exported files according to the help text.
4. Restart Hierarchy Manager
5. Check hman.log