I would also suggest deleting any emails from him rather than having them sit there unopened. Do you have a way to block his emails?
Most email services have a way to automatically route emails from certain addresses into another folder, so you can ignore them until you need them (which you may, if he's still drunk and ranty).
In my experience through the divorce/custody process, document everything. Just have written, dated records of any agreements, conversations, or breaches of regular boundaries, and file them away for a later date.