Newsletter Send Confirmation Page - Weirdness Abounds!

After we moved to a new server, when we go to send a newsletter, you normally would see a green checkmark for every email that was sent. However, on this new server, whenever we sent a newsletter, we see a green checkmark, and then a TON of garbage characters being outputted to the screen.

The emails apparently get sent to at least SOME of the addresses, but I question if the HTML subscribers are getting it because of this problem. Any ideas why that part of the script would spit out that nonsense?

I'm attaching a screenshot. Any idea why this is?

Searching the forums for 'email garbage' reveals:

http://www.zen-cart.com/forum/showthread.php?t=52328

Stevesh - Thank you! That certainly helped. I narrowed the problem to being the GZip compression. When I turned it off in the Admin Configuration, I didn't see those characters.

Is there any side effects for not having GZip Compression on? In other words, will having that off make the site slower?

If so, how can I make this new server GZip enabled?

Any help would be appreciated, mate.