It seems odd that there was no reply to this post in over 2 years. I just had the same zone chat issue myself; not limited to ESD, but any/all zones anywhere in the game (I'm level 50, and I've been all over the map). I sent in a support ticket and received a response to check my Privacy settings under Social. In doing so, I found that "Allow only friends and fleet to Chat" was set to "Off" (as expected, and is set that way on all my characters). In guessing that this affected zone chat, and thinking something was perhaps mis-set somewhere, I changed it to "On" and saved it, then changed it to "Off" and saved it, and... voil? - zone chat works again.
Hope your mail issue was resolved; guessing that after 2 years it must have been...
Mac mini Server (mid 2011): 2GHz Intel Core i7, 8GB 1333 MHz DDR3, Intel HD Graphics 3000 512MB
OS X El Capitan 10.11.2
Comments
Not sure how to reproduce so I didn't submit a ticket, but definitely a bug.