Q: Whitelist for Greylist setup

I have tried to follow the guidelines in the Apple Server manual for adding some servers to the whitelist for not beeing grey listed, but I cant get it to work.

Have followed the following steps:

Add known servers to a whitelist

When you create a whitelist, you’re listing servers that are known good servers.

1. Create a text file: touch host-whitelist.txt
2. Edit the text file: vi host-whitelist.txt
3. Add the following three lines, replacing the name on the third line with the name of the mail server you would like to whitelist:
4. mail:command = writeSettings
5. mail:skipReadSettings = yes
6. mail:configuration:postfix:host_whitelist:_array_index:0 = "goodMailServer"
7. Load these settings into serveradmin: sudo serveradmin command < host-whitelist.txt

In the host-whitelist.txt file have I setup multiply servers like this:

mail:command = writeSettings

mail:skipReadSettings = yes

mail:configuration:postfix:host_whitelist:_array_index:0 = "server1"

mail:configuration:postfix:host_whitelist:_array_index:1 = "server2"

mail:configuration:postfix:host_whitelist:_array_index:2 = "server3"

mail:configuration:postfix:host_whitelist:_array_index:3 = "server4"

mail:configuration:postfix:host_whitelist:_array_index:4 = "server5"

When I execute the sudo serveradmin command < host-whitelist.txt do I get the following error:  command must be of the form 'serveradmin command service:command = command_name'

What do I do wrong here?