Good Afternoon,

I'm working on a environment which is returning this message:

You are using 105% of 600,000 Software Units

What's the maximum percentage after which i'm unable to publish eSpaces?

TIA,
J Kaufman

Please contact your account manager as soon as possible to evaluate options, if you're in this situation.

From my personal experience the margin is 5%. But don't worry, that "You are using 105%" message means your SUs are in interval ]100%,105%]. It can be either 600001 or 630000, so you may have some more of SUs to spend in case of extreme urgency.
You can check the exact value in ServiceCenter -> Administration -> Software Units. Click to see in detail what espace is consuming how many Units.

If deleting useless stuff can't solve the problem, your Account Manager (and a possible license increase) is the only way.