multiple domains in one zone file

[Techdog]

Ok, I am learning here.

Now, I have a number of domains on my primary server and they are all listed
in one zone file.

The NAMED.BOOT file looks like this:

primary domainone.com domains.db
primary domaintwo.com domains.db
primary domainthree.com domains.db
primary domainfour.com domains.db
primary domainfive.com domains.db

and so on.

The domains.db file looks like this:

domainone.com.   IN  A   123.123.123.1
domaintwo.com.   IN  A   123.123.123.2
domainthree.com.   IN  A   123.123.123.3
domainfour.com.   IN  A   123.123.123.4

and so on.

Is this incorrect?

Here is the problem: My secondary is having problems getting all this
onformation into its zone file. It gives error messages about how the
primary server is not SOA for all these domains.

Is it a bad thing to list multiple domains in one zone file? How do I
establish SOA for each one?

I really appreciate all the help!

TD