MessageHi Thomas, Thanks for the lead. There really wasn't anything very relevant arising from a straight forward search for "SMTP Relay" (with or without quotes), however, following a long rabbit trail of links that started in a tangentially relevant article, I was able to locate a document with very relevant content about a third of the way through: www.isaserver.org/img/upl/exchangekit/2003messagescreenerintrelay/2003messagescreenerintrelay.doc One must add the domains you want to restrict receiving to, to the Domains node beneath the virtual SMTP server. I had been slogging through the properties of the service itself, and what is done with the domains is not clear from the UI or the help. Apparently, only the remote domains listed accept incoming mail, but if you have no remote domains, it accepts all comers. Strange design. Now that I've done this, and allowed anonymous connection, I can receive bounces, and I am not an open relay (not strictly -- any mail is accepted by the service, but nothing is actually forwarded for delivery unless it's addressed to my domain). However, any mails sent outright to my domain bounce with an SMTP 5.3.5 config error, which is some kind of loop back problem. Anyone have insight into that? Again, extensive Googling is not getting to the heart of this. I only have one virtual SMTP server, and no connectors to Exchange or anything else. Best, --Bob ----- Original Message ----- From: Thomas W Shinder To: [ExchangeList] Sent: Tuesday, June 29, 2004 9:06 PM Subject: [exchangelist] RE: SMTP Service http://www.MSExchange.org/ Hi Bob, Go to www.msexchange.org and www.isaserver.org and you'll find some great tutorials on SMTP relay. HTH, Tom Thomas W Shinder www.isaserver.org/shinder ISA 2004 Beta - Get it now! http://www.microsoft.com/isaserver/beta/default.asp ISA Server and Beyond: http://tinyurl.com/1jq1 Configuring ISA Server: http://tinyurl.com/1llp -----Original Message----- From: Bob Grommes [mailto:bob@xxxxxxxxxxxxxx] Sent: Tuesday, June 29, 2004 10:30 PM To: [ExchangeList] Subject: [exchangelist] SMTP Service http://www.MSExchange.org/ I have a W2K box that runs just the SMTP service. It's used to send out emails to a couple thousand subscribers to our reminder service a couple of times a month. These are emails put into the SMTP server's queue by a custom application that generates them. We don't actually use Exchange or anything else on this box, it's just a stand-alone unit isolated from our corporate network for safety's sake. I'm a bit of an email administration virgin, so forgive me if this is a naive question ... but if I uncheck the box in the SMTP service that allows anonymous logins, so that I'm not an open relay -- then any mail that gets sent to that box gets bounced. How do I allow emails to my own domain in, from all comers, without being an open relay? I want to catch repy-to's and bounces of the mails I'm sending. The bounce error says, "relay refused" but that wouldn't be a relay, it'd be a delivery. I've Googled around but can't find anything that addresses my scenario. --Bob