The name has historic reasons

and is mostly unique...
I did that: telnet returns after about 25 seconds without any information dumped to the console, as if the socket is closed. A process /opt/zimbra/libexec/zmmailboxdmgr is running all the time, also during the connection attempt with telnet. The zmmailboxd.out does not receive a new entry during the telnet.
What's going wrong here?
Sven