Hi,
my suggestion is adding a feature so that user could limit not the number of incoming messages but time that given temporary address is valid.
Proposed format is:
someword.12h.user@spamgourmet.com
would make address valid for 12 hours
someword.3d.user@spamgourmet.com
would make address valid for 3 days
someword.3w.user@spamgourmet.com
would make address valid for 3 weeks
but of course you could make it differently.
regards,
Kvas