Hi Brian, Are you using a dial up connection or the dreaded PPPoE? Its very unusual for a packet filter to conk out without the help of dialup or the PPPoE kludge :-) Thanks! Tom Thomas W Shinder www.isaserver.org/shinder <http://www.isaserver.org/shinder> ISA Server and Beyond: http://tinyurl.com/1jq1 Configuring ISA Server: http://tinyurl.com/1llp <http://tinyurl.com/1llp> -----Original Message----- From: Rogers, Brian [mailto:RogersB@xxxxxxxxxxxxxx] Sent: Wednesday, August 13, 2003 1:13 PM To: [ISAserver.org Discussion List] Subject: [isalist] RE: Configuring an SMTP Relay on the ISA Server Firewal l http://www.ISAserver.org Along these same lines (well not really..but close) It would appear for some reason our ISA Server (win2k sp3/isa sp1) all the sudden decided it was going to block all incoming traffic on port 25. The only solution found was to disable, and reenable the packet filter allowing SMTP in/out 25. I found this very odd.