Hey guys, I thought I'd give the SP1a SMTP filter another chance. I've had it running for about 5 days without a problem, but last night I get this in the Application Log: Event Type: Error Event Source: SmtpEvt Event Category: None Event ID: 20031 Date: 4/5/2002 Time: 7:44:40 PM User: N/A Computer: ISASERVER Description: An unknown SMTP command For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. Data: 0000: 45 54 52 4e 20 40 54 48 ETRN @TH 0008: 45 52 4d 4f 54 49 43 44 ERMOTICD 0010: 45 56 45 4c 4f 50 4d 45 EVELOPME 0018: 4e 54 53 2e 43 4f 2e 55 NTS.CO.U 0020: 4b K Looks like the same stuff we saw before SP1 was taken down. Anyone else seen this? Thanks! Tom www.isaserver.org/shinder