Hi all,
Thanks for your inquiry, and sorry that this forum question has been overlooked.
On the supervisor machine, in the QBDIR/etc/ folder (/usr/local/pfx/qube/etc on linux, C:\Program Files\pfx\qube\etc on windows, and /Applications/pfx/qube/etc on Mac), you'll find a few plain-text email template files, named job.mail, subjob.mail, etc.
You may edit the "From:" line of these template files to get the effect you desire.
I hope that helps... Thanks!
-shinya.