So bringing it back to the original question, what is a reasonable expectation for the time frame for a hotel to mail the items (assuming they find it and have the opportunity to mail it)?

Clearly, some items can be mailed at leisure and I will be happy to receive them. Some items may be needed much more urgently (what if I left a passport, e.g.). And there is everything in between.

A question for William perhaps: Are there any SPG guidelines given to hotels on mailing back left behind items or is it entirely up to the discretion of the individual hotels?