If you're using 64-bit Linux server, you need to create a symbolic link from StandardERPServer64-Slave to StandardERPServer-Slave, otherwise it doesn't work. This is a bug I reported many years ago.
8.5 2023-04-19 (build 85550290)
In the server on the first run:
2025-10-29 09:07:29 Requesting Lookup address
2025-10-29 09:07:29 Failed to create e-mail back, unknown source register
What th...