I did reproduce on trusty.
I tried again on wily/xenial. If I run the steps to completion I do end up with a suid/sgid escalate executable owned by ubuntu:mail, but './Test/mail/escalate /bin/sh' still only gives me a process running as ubuntu:ubuntu.
I did reproduce on trusty.
I tried again on wily/xenial. If I run the steps to completion I do end up with a suid/sgid escalate executable owned by ubuntu:mail, but './Test/ mail/escalate /bin/sh' still only gives me a process running as ubuntu:ubuntu.