++jdporter for the sarcasm. And thanks for the prod that quite a while has passed but nothing else has happened on this thread.

One of the nightly cron jobs runs a query like:

update message set folder = folder-1 where -3 < folder and folder < 0;
[download]

and then deletes rows where folder has reached -3 (roughly).

So I think it is actually between 2 and 3 days before a "deleted" message is irretrievable, depending on the time of day when it is "deleted".

You can find -3 hard-coded quite a few places in the other bits of code that deal with "message folders". So we could lengthen the grace period by updating all of those (as well as, I think, just the one instance of "-3" in one cron job).