AG, my guess as to why he's sending more emails is to keep the communication channels open. A lot of the WAS are like teenagers, they don't want you around but secretly (even to themselves) want your love and attention.
It's probably not even worth trying to figure out why he's sending more emails. I think you are right to send one response back, just make it as short and business like, without being rude, as you can.
Me 43 W 38 M 5 T 7 SD20 S15, S13 with 1st W ILYBNILWY June 2010 Separation/Bomb July 2010 Divorce Feb 8, 2011