Uh, I think you need a little sleep, all you need to do is have your clients use SMTP authentication. But I'll have to mention that this will not prevent spammers sending mail to valid local users, and forging their from address. Your best bet would be to incorporate a spam blocker such as Declude.
Jason -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of [EMAIL PROTECTED] Sent: Monday, June 03, 2002 9:42 PM To: [EMAIL PROTECTED] Subject: [IMail Forum] Preventing Self-referential Spam This might be obvious, but I'm stumped right now: How do I stop spammers who send email with a From: address as the same as the To: address? For instance: * I have a mail server MAIL.ACME.COM * I have a valid user [EMAIL PROTECTED] What's to stop someone from sending an email to [EMAIL PROTECTED] from [EMAIL PROTECTED] (with Reply-to as [EMAIL PROTECTED]) via my SMTP server? Note that [EMAIL PROTECTED] could access my server via any of a zillion different Internet connections (from the LAN at his office, from his dialup ISP while on the road, from his cable modem at home, from a client worksite, from the Moon, etc.) -- that means I can't just allow specific IP ranges to connect via SMTP. Do I just need more sleep, and this is really obvious? Or is this as tough as it appears to me right now? Mike Please visit http://www.ipswitch.com/support/mailing-lists.html to be removed from this list. An Archive of this list is available at: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Please visit the Knowledge Base for answers to frequently asked questions: http://www.ipswitch.com/support/IMail/
