>> Commenting out the rules should work, but that leaves your server open
>> to abuse. Better would be to tell your users to use whatever mail server
>> their ISP tells them to use; this server is presumably willing to relay
>> mail for them. If their ISP won't relay mail for dialup users, they
>> should go get a real ISP.
>If your going to allow off-campus relaying, be sure you have a lot of
>time to deal with spammers abusing your box.
All the anti-relaying rulesets I know of allow you to list sets of IP
numbers that are allowed to relay to whoever they wish (I dynamically
get such an IP number and use mail.telstar.net to relay mail from my
flat, and it just works). Assuming your IP is not whitelisted then
using mail.telstar.net as an abuse relay emits 551 (I tested this
after implementing this feature).
Users *should* be using their ISP's mail relay---if they can not or
this is broken then they should get a real ISP (i.e. one not using
NTmail as a basic first step, because NT mail violates the internet
host requirements in various cripling ways).
If you let anyoine relay be prepared for what advanced the
anti-relaying project on mail.telstar.net (it was a long term goal
before, this moved in up to top prioirity). Not only where 3 spams
relayed in 4 days but the last spam sent over 1,000 bounces to
postmaster (multiple people, including me). I know from personal
experience that pine *really crawls* when faced with multiple-Mb 1,400
email message mail boxes.