Remove FillInReplyTokensTransition

Removing this because we now have a not null constraint. It is
impossible to test this transition.
Default emails from team@trailmix.life
Use email reply token instead of today@trailmix
Support old emails to today@ at the same time

There are probably some folks that will take a day or so to reply to
older emails. We should support both until we don't see anyone hitting
today@trailmix.life.
Revert "Support old emails to today@ at the same time"

This reverts commit c8617301fe0cece17a5dc936d83d2fea704e81c2.