I've successfully used the MailEnvelope property to prepare emails that will
send a range (once the user reviews the data, personalizes the introduction,
etc.) within a spreadsheet but now find myself having to deal with a twist.
The data is filtered, so some rows of the selected range are hidden and
should not be viewable by the mail recipient. When emailed using
MailEnvelope I found that the hidden rows become unhidden when the recipient
replies. Presorting is not an option. I considered copying just the desired
data to a separate sheet and sending it, but then how do I get rid of this
extra sheet automatically (I don't know of an event that triggers when you
hit Send under these conditions).

Any ideas for emailing this filtered data using MailEnvelope?