I use a knoppix 4.0.2 DVD on my work PC when I travel (so I don't have to put up with windows). I have it running nicely with a persistent home directory on a USB key. The only thing I can't do at the moment is send mail from (e.g.) Thunderbird. I'd like to be able to run an MTA which only listens on 127.0.0.1 and will only relay clients connecting on that IP.
Can anyone offer simple instructions on how to set this up? Can I just run smail under its default configuration on the DVD or will that leave me hanging off the internet running an open relay?
If I need to alter the config, it seems I can add this to my persistent config drive. Is this the case?
Thanks for any help you can offer.
Matt.

Windows XP, Vista, 8.1, Linux Knoppix, Office XP, (6 CDS)
$10.00
KNOPPIX 9.1 Linux Install & Live DVD 32bit & 64bit
$19.99
Knoppix Live GNU Linux System 9.1 on Bootable CD / DVD / USB Flash Drive
$5.99
KNOPPIX USB DVD OS , BEST OF ALL HIGHLY RECOMENDED
$11.99
VINTAGE SOFTWARE | KNOPPIX STD 0.1 (SECURITY TOOLS DISTRIBUTION)
$7.57
Knoppix Linux Bootable OS v8.6 "Original Live Operating System" 16G USB Stick
$20.85
$8.00
Knoppix Linux Bootable OS v8.6 "Original Live Operating System" 32G USB Stick
$21.42
$7.00
Knoppix 5.0.1 ULTRA RARE Linux DVD - Linux Pro Extra August 2006
$34.01