1.a.Which keys are used to erase input, interrupt a program, freeze the terminal, and unfreeze the terminal?
b.What utility notifies you of the arrival of electronic mail by beeping and raising the flag on a mailbox icon?
1) Freeze : Ctrl+S
UnFreeze : Ctrl+Q
Erase Input : Ctrl+W , Alt+3, Esc+3
Interrupt a program : Ctrl +C
2) There are many utilities like OpenSMTPD, Postfix, or Exim4