Re: [Exim] yahoo.com makes callout senderverify unusable!?

Kevin Reed writes on 12/4/2003 10:51 AM:

> Example: A seller on Ebay will use a free account like yahoo, msn,
> hotmail as their mail address, but will send mail via Ebay's mail system.
>
> Now are you going to reject a message because it came from Ebay but has a
> Yahoo address?? If you do, how are you going to communicate with them?

1. helo yahoo.* from any IP that doesn't have yahoo rDNS = FAKE

2. mail from: *@yahoo.* from an IP that doesn't have rDNS / has generic
cable / dsl looking rDNS = fake

The rule #2 has some amt of collateral (geeks who run their own
sendmail, or some corporate mailservers that run on DSL lines) - but
catches a whole lot of spam