it will only list directories present in the current dir and neither files nor contents of subdirs.
It is useful if a dir contains many files and you need to print the list of subdirs only.
echo "this is a mail body\n~c other@example.com" | mailx -s "my subject" user@example.com
This will send mail To: user@example.com Cc: other@example.com Subject: my subject
this is a mail body ------------------------------------------------- the '\n~c other@example.com' will add the recipient to Cc list, as '~' tilde option only recognized by mailx cmd if present at start of line