That would probably work. Use your registrar's nameservers, create an MX entry, but not an A entry.

You could try it out.

A nicer solution (neater really) would be to put it on as an addon domain, with a blank index page. That way would be much better.

Justin - if you're only going to use the domain for email, then why not just use the email forwarding feature that the other hosting company will probably have.

I do this with my Registrar (BuyDomains) and it works fine for me.

No need to park or add-on or nothing.  Just forward the otherdomain email addy to a mailbox account that you create at your maindomain account at LP.

You then retrieve email under your LP user mailbox (since the other hosting company is forwarding it to that mailbox) then to send out email with your other domain addy, just enter that in the "reply email address" config.

It's really that simple.  

Okay, but there's really no need to do that because you still can treat the other domain as if it's a separate account.

Maybe I wasn't clear in my explanation.

Example:

Let's call the maindomain hosted at LP = "hello.com"
Let's call the otherdomain without hosting = "welcome.com"

Via LP's cPanel, create mailbox user "welcome"

At the Registrar, you would forward "wecome.com" to "welcome@hello.com"

In email client, set message rules so that:

"orders@welcome.com" go to subfolder "Order" in the "Welcome" folder
"webmaster@welcome.com" go to subfolder "Webmaster" in "Welcome" folder
"support@welcome.com" go to subfolder "Support" in "Welcome" folder
etc.
etc.

Each email addy gets organized into it's own folders so that it doesn't get mixed up in your "Inbox" folder with all your other email.  By creating message rules which sends email directly into folders and subfolders by the criteria indicated, it makes for easy and fast referencing and you know exactly what came in from where.

You can also send out email as "support@welcome.com", "orders@welcome.com", etc.

Anyway, this is a way to have two or more businesses organized separately, yet not have to use or pay for unnecessary additional features that you don't have to.  Like I said, I do this myself and it works great.

I guess I just don't see why you need to park it, but you need to do what you need to do.

I'm only giving you a suggestion that works for me and thought it might work for you, too.

LOL!