[beej@www ~]$ head -1 /usr/sbin/system-switch-mail
#! /usr/bin/env python
[beej@www ~]$ which python
/usr/local/bin/python
[beej@www ~]$ sudo /usr/sbin/system-switch-mail
Password:
Traceback (most recent call last):
  File "/usr/sbin/system-switch-mail", line 89, in <module>
    main()
  File "/usr/sbin/system-switch-mail", line 76, in main
    from switchmail_tui import mainDialog
  File "/usr/share/system-switch-mail/switchmail_tui.py", line 36, in <module>
    from snack import *
ImportError: No module named snack


manually using /usr/bin/python works as designed