If I set my file creation mask (umask) in ~/.login, will the mask be the same when I start another shell ?
When you start another shell using rlogin or telnet, your umask will be the same whether you put the umask command ~/.login or ~/.cshrc, however the best place to set your umask is in ~/.cshrc, as some programs like rsh source ~/.cshrc when carrying out commands on remote systems. Make sure to place the umask command before the non-interactive-shell check.