However, I do wonder about it's usefulness. This is meant as an anti-spam measure, right?
Yeah.
Wouldn't most addresses (even spammer ones) be valid at the host they *claim* to be from?
That's what I want to find out. There's a lot of made-up addresses in your average spam, and Courier already rejects a lot of them for using non-existant domains.
-- Either they set up a valid address long enough to send out the mails, or they don't care about direct replies and they can hijack an address (not the account itself, but just *use* the address in headers and SMTP commands) from some other domain ... *any* address from *any* domain ... Yes?
Yep. I work with someone who suggests that this technique is effective, and that he's used it in the past. This implementation is fairly simple, and should let us see how effective it is. If it cuts down on spam, I'll end up using it in production.
Are there any services that will give different responses to those two commands?
Anyway, as for RCPT vs. VRFY responses... You know some servers reject VRFY out of hand to cut down on address harvesting, right?
Yes, and those that do generally just respond in the positive for all addresses. They also tend to give positive responses for non-existant addresses to the RCPT command, to prevent it from being used as a simple replacement for VRFY. I'm not sure that's always the case, though. I'd like to know if anyone can point out services that don't work this way.
(It can't stop it of course, but it helps somewhat so long as harvesters prefer using the VRFY command.) So those servers will obviously give differing responses to RCPT than to VRFY.
I expect the opposite to be true in most cases, but I'm looking for specific cases where the responses differ.
------------------------------------------------------- This SF.Net email sponsored by: Parasoft Error proof Web apps, automate testing & more. Download & eval WebKing and get a free book. www.parasoft.com/bulletproofapps1 _______________________________________________ courier-users mailing list [EMAIL PROTECTED] Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-users
