Question - Mez and Slow Immune

[Caram]

Some mobs are immune to slow "XXX is immune to changes in speed" or immune to Mez.

Is there a way to catch that in a condition "don't bother trying to mezz if it's unmezzable" etc?
Given the message comes back on slow there should be a way to trap that message, but I don't see it. Unmezzable is harder.

 

[Myysterio]

Some mobs are immune to slow "XXX is immune to changes in speed" or immune to Mez.

Is there a way to catch that in a condition "don't bother trying to mezz if it's unmezzable" etc?
Given the message comes back on slow there should be a way to trap that message, but I don't see it. Unmezzable is harder.

My bard drops targets off if they're immune to mez. It even announces it globally over eqbcs when they are. It's built into 12.0 I think.