It seems like the sieve / filter rules have no way to re-order. Can the IDs be changed in the database, or is there some way to force reorder the filter rules?
You probably could change the IDs in the database, but that's a pain. Using a mangesieve client like roundcube is probably the best option for end users right now. I don't know if this has a rfe filled for it, but could use one of not.
