Hi Rob, That'd be changing the permitted SMTP command length, by any chance ? If it is, I don't have to update my personal knowledgebase after all and I can have my dinner in peace. ;) Regards, Paul _____ From: Rob Moore [mailto:RMoore@xxxxxxxx] Sent: maandag 31 januari 2005 17:56 To: [ISAserver.org Discussion List] Subject: [isalist] RE: SMTP error http://www.ISAserver.org Those were the details. I did find something on EventID.net that pointed me to the command XEXCH50. I then found a KB article (812455) about that command, which I entered into the SMTP filter. Since entering that command into the SMTP filter 10 minutes ago, the error has not recurred. I'll keep watching for it. Rob This e-mail and any attachment is for authorised use by the intended recipient(s) only. It may contain proprietary material, confidential information and/or be subject to legal privilege. It should not be copied, disclosed to, retained or used by, any other party. If you are not an intended recipient then please promptly delete this e-mail and any attachment and all copies and inform the sender. Thank you.