Yeah, I thought that's what you meant. It's sort of like you said but not quite, outgoing mail uses a protocol rule, that goes out as the primary IP, incoming mail is using a publishing rule and can use any external IP, you can send mail out of one and have it come in another :) Still don't understand why you couldn't get mail coming in if you had for your MX entry using the same external IP that you used for the publishing rule. Does that make sense :) Cheers Phill _____ From: Glenn Maks [mailto:gmaks@xxxxxxxxx] Sent: Wednesday, 7 January 2004 8:59 AM To: [ISAserver.org Discussion List] Subject: [isalist] RE: Thanks alot ISA now working BUT Exchange behind ISA http://www.ISAserver.org I think I have that right, recently I "Published" my internal MX server and used one of the many IP addresses I bound to the External Interface, But not the Primary, I was able to send mail but not receive, what was happening was this, My MX server was published in DNS using a IP address bound to the External NIC of ISA, using one of the secondary IP addresses, again, NOT the primary, all mail leaving ISA would take on the Primary IP address assignment, not the IP address I published my MX server with in DNS, that was one of the secondary IP's, and I was using Publishing Rules. -----Original Message----- From: Phill Hardstaff [mailto:phillh@xxxxxxx] Sent: Tuesday, January 06, 2004 4:22 PM To: [ISAserver.org Discussion List] Subject: [isalist] RE: Thanks alot ISA now working BUT Exchange behind ISA http://www.ISAserver.org Glenn, don't you mean "you should know that ISA uses the Primary IP address assignment when used in conjunction with Protocol Rules" where you said "you should know that ISA uses the Primary IP address assignment when used in conjunction with Publishing rules" ? Cheers Phill --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.558 / Virus Database: 350 - Release Date: 2/01/2004