ADF clarification

[Steel God]

When do the auto defensive fire rules in the A/I menu get applied in PBEM phase based games? ADF is of course enabled in the options.

I can change the settings during my move phase but obviously it does not make sense to apply these changes on my opponents pending defensive fire phase.
So will the game save my new settings and apply them during my next defensive fire phase or how does this work?

Not sure I follow the bit about making changes during the turn, the rules are set at the beginning of a PBEM match and stay that way until the match is over. 

That said, in phased PBEM play (which is the only way I play), Player 1 completes his movement and advances the turn/phase.  The AI will conduct ADF for player 2 and fire defensively at full strength against targets it determines, and the A/I will then advance the phase to player 1's fire phase.  Player 1 then manually conducts their fire, advances the turn/phase and you move to player 1 melee phase.  At the end of the melee phase you advance turn/phase again, and the file is ready to be emailed to your opponent.  Same thing will happen on their turn (with player 1 in example above being player 2).  In this way PBEM is played with phased play and only 1 email exchange required per turn.