DNS internal server not pinging properly?

There isn't enough data in your post to answer your question.

Running a DNS server means nothing as far as resolution unless your clients (including the DNS client running on the machine itself) are configured to use it for resolution.

In other words, if your server's address is 192.168.1.2 then you need to add 192.168.1.2 (or, equally, 127.0.0.1) as the DNS server to use in System Preferences -> Network.

If your network settings are configured to use 4.2.2.1 (or anything else for that matter), then that's the server that will be used, regardless of the fact there's a DNS server running on this machine.

There still isn't enough information in your post to answer your question.

Let's start with:

Company 1 WORKS internally/locally. Company 2 does not.

What do you mean by 'WORKS'?

Do you mean clients can resolve the addresses? access the services?

Are you talking about internal clients? external clients?

Where are you checking from?

As for your earlier post;

I have the 4.2.2.1 setup as a secondary for answering outside requests

This is not correct. If you ever want to resolve internal addresses then your clients should ONLY use your internal DNS server. That server should be able to resolve non-local domains through recursion (preferred) or forwarding, so this doesn't prevent your internal clients from resolving remote domains, but expecting to put a public DNS server in their list of resolvers is not the way to do it.

"Works," of course, means it resolves the address correctly to the local address. I'm not sure what else it could possibly mean.

Then you've clearly never worked in technical support 🙂

A typical support caller will use the term ' it doesn't work' for everything from 'I can't find the power switch' to 'why doesn't XYZ app correctly factor operators of the second quanitzation of QFT'.

As such, it isn't clear to me that your clients are able to resolve the addresses you expect, or if they are, they get the results you expect.

Indeed, in one post you say:

mail.company2.com 192.168.1.2

www.company2.com XX.XX.XX.XX (2nd external IP)

But go on to say:

No idea why server.company2.com and mail.company2.com won't break down locally at all

Which seems to contradict what you're saying, since it appears that mai.company2.com is resolving the internal address (which is what I assume you mean by 'break down' since that's not a common DNS-related term).

Even so, it's still possible that the addresses resolve as expected, but you can't access the site in a browser. For 99.9% of users, not being able to resolve the hostname and not being able to load the site in the browser amount to the same thing and would still fall in that 'doesn't work' classification. However, that could be the result of DNS failure, or web server misconfiguration, or port forwarding in your router, or any number of other things.

So, therefore, I don't think it inappropriate to ask for clarification.

It's a good idea, IMO, to have the external DNS in case the internal DNS fails

Unfortunately you're wrong there 🙂

First off, your internal server shouldn't fail. Secondly, if you're that worried, setup a second internal server to hand out to your clients. Having clients use external DNS will, at some point, result in more calls because users will be using that external server without even realizing it, and things won't work as they expect.

I'm sorry to hear I can't help you. I'm even more sorry that you can't hear what I'm saying.

Good luck.