Hi Pete/Ben, Thank you for your response. We have enabled Site-Specific logging for a few domains but more specific we have done it for our domain (aip.org). Below is an example of a probe failure for one of our email addresses. In this case [log in to unmask] is a valid email address here so I am still unsure as to why the probe fails. This is affecting many of our other lists and we are receiving many complaints from subscribers who have been auto-deleted. Listserv Daily Log: 17 Mar 2006 14:52:18 Distributing mail ("FYI_MAILING") from owner-fyi@LISTSERV.AIP.ORG... 17 Mar 2006 14:52:18 Mail posted via SMTP to [log in to unmask] SQL> SELECT EMAIL,NAME,FYI FROM LISTSERV WHERE UEMAIL LIKE ? FOR UPDATE OF EMAIL,NAME,FYI,UEMAIL 17 Mar 2006 14:52:34 -> Probe failure for [log in to unmask] on FYI LSMTP Accounting Log: 5 145232 1.001E5AA6 SMTP <192.58.150.56> <192.58.150.54> <> <> 21011 13 <owner-fyi*djones**AIP*[log in to unmask]> <[log in to unmask]>. From what I understand "5" is a successful transaction. LSMTP Site-Specific Log: 14:52:26 ( 75)O opened AIP.ORG beast.AIP.ORG 14:52:26 beast.AIP.ORG( 75) >>> 220 beast.int.aip.org AIP MAIL GATEWAY Fri, 17 Mar 2006 14:52:26 -0500 14:52:26 beast.AIP.ORG( 75) <<< EHLO speedy.bulk.aip.org 14:52:26 beast.AIP.ORG( 75) >>> 250-beast.int.aip.org supports the following ESMTP extensions: 14:52:26 beast.AIP.ORG( 75) >>> 250-DSN 14:52:26 beast.AIP.ORG( 75) >>> 250-8bitmime 14:52:26 beast.AIP.ORG( 75) >>> 250 OK 14:52:32 beast.AIP.ORG( 75) <<< MAIL FROM:<owner-fyi*djones**AIP*[log in to unmask]> BODY=8BITMIME 14:52:32 beast.AIP.ORG( 75) >>> 250 <owner-fyi*djones**AIP*[log in to unmask]>: Sender Ok 14:52:32 beast.AIP.ORG( 75) <<< RCPT TO:<[log in to unmask]> 14:52:32 beast.AIP.ORG( 75) >>> 250 <[log in to unmask]>: Recipient Ok 14:52:32 beast.AIP.ORG( 75) <<< DATA 14:52:32 beast.AIP.ORG( 75) >>> 354 beast.int.aip.org: Send data now. Terminate with "." 14:52:32 beast.AIP.ORG( 75) <<< . 14:52:32 beast.AIP.ORG( 75) >>> 250 beast.int.aip.org: Message accepted for delivery 14:52:35 beast.AIP.ORG( 75) <<< QUIT 14:52:35 beast.AIP.ORG( 75) >>> 221 beast.int.aip.org closing connection. Goodbye! 14:52:35 ( 75)O closed AIP.ORG beast.AIP.ORG Thanks in advance for your time, Mike ----- Original Message ----- From: "Ben Parker" <[log in to unmask]> To: <[log in to unmask]> Sent: Tuesday, March 21, 2006 11:18 AM Subject: Re: Turn Probing OFF > On Tue, 21 Mar 2006 09:03:57 -0500, Michael DeGregory > <[log in to unmask]> wrote: > > >It seems the probes are failing on valid email addresses though and I can't > >understand why. > > To learn this you have to do site-specific monitoring of the SMTP email > transaction with the receiving site(s) for the addresses in question. > Probe-Failed either means the address is truly not there (it should fail) or > the receiving site mail server (incorrectly) objects to the format of the > RFC821 return-path address: > MAIL FROM:<owner-nolist-xyz*mdegrego**LISTSERV*-AIP*[log in to unmask]> > > If the site ojects to this return-path format, you can either give up on > mailing to such addresses or try to convince the receiving site to make > their mailer compliant with email standards RFC821 and RFC 2821 so they will > accept return-paths formatted in this way. > > Since you are using LSMTP as your mailer, Site-Specific logging is easy. See > http://www.lsoft.com/manuals/lsmtp-faq.stm#2.6