Technically, he doesn't work with Mesa Enchantress the way you are thinking. When the enchantment comes into play with the Mage, it doesn't count as casting an enchantment spell. You are merely putting it in to play. If the wording was, "...still in play, cast it without paying its mana cost," then you would be casting the spell. Otherwise, the enchantment is coming into play as the result of the Mage's triggered ability.
Posted By:
Kenji18
(4/24/2010 9:56:54 AM)
Mythic Proportions or, even better, Eldrazi Con***ion
Posted By:
Revan312
(8/13/2010 1:29:18 PM)
@ DacenOctavio Painter's servant solves just about every problem.
Posted By:
Boakes2047
(5/15/2011 12:04:42 AM)
13/13 with trample and annihilator 2 for 
(and no card disadvantage) via eldrazi con***ion
Posted By:
metalevolence
(11/16/2010 6:42:57 PM)
The reason Wurmweaver Coil can only enchant green creatures.
Posted By:
A3Kitsune
(3/9/2010 10:49:56 PM)
@Weretarrasque: What would make you think it counts as playing an enchantment?
Posted By:
SweetZombiJesus
(11/18/2010 9:37:19 AM)
@ A3Kitsune:
Painter's Servant solves that problem.
Posted By:
DacenOctavio
(2/2/2011 1:50:26 PM)
Enchant with Followed Footsteps, then enchant the second with Flickerform, and finally make sure to have a Mesa Enchantress down and you just scored a toolbox-life gain deck.
Posted By:
ZioKai
(8/10/2009 10:05:56 AM)
Armored Ascension, anyone?
Posted By:
DiasFlac420
(4/18/2011 3:04:00 AM)
Reasonable in edh ((find that eldrazi con***ion)
Posted By:
NeverendingDream
(5/25/2011 12:54:22 AM)