bbs.spamgourmet.com

taskman-paypal@spamgourmet.com

Is now unneeded. How can I delete/deactivate it?

you can disable it by setting the forwarding address to be blank and then saving.

Will Spamgourmet try to forward the messages to "blank" and waste your resources or does it recognize "blank" as a disabled account?

having a blank forwarding address is about the same as having no account -- it gets ignored. Basically, the address has to be parsed no matter what, then a database query is made for the username to see what comes back. If either a) there's no user account record, or b) there's no fowarding address (this is stored in the user account record), then the message is ignored.