Date: Thu, 14 Dec 2000 15:36:31 -0600 From: "Jason Young" <jyoung@accessus.net> To: "Chuck Rock" <carock@epconline.net>, <freebsd-isp@FreeBSD.ORG> Cc: <mdickerson@officeonweb.net> Subject: RE: sendmail NOQUEUE: Null connection from some.domain [a.b.c.d] Message-ID: <NEBBIHDFEDCADAEBJEKAOEFFCJAA.jyoung@accessus.net> In-Reply-To: <004701c065ee$b53539c0$1805010a@epconline.net>
next in thread | previous in thread | raw e-mail | index | archive | help
A "null connection" is when sendmail gets a connection to its TCP port, and sends its banner, and the remote client either A) closes the connection without doing anything or B) issues only the QUIT command, which closes the sendmail connection immediately. Try telnetting to your mailserver port 25, and then closing the telnet without doing anything. You'll see it. Chuck's SNMP monitoring system is probably checking to see that the SMTP service is up and running by connecting to its TCP port. Jason Young Access US Chief Network Engineer > -----Original Message----- > From: owner-freebsd-isp@FreeBSD.ORG > [mailto:owner-freebsd-isp@FreeBSD.ORG]On Behalf Of Chuck Rock > Sent: Thursday, December 14, 2000 10:56 AM > To: freebsd-isp@FreeBSD.ORG > Subject: RE: sendmail NOQUEUE: Null connection from some.domain > [a.b.c.d] > > > These messages pop up in my logs from my SNMP machine monitoring > the status > of my mail server. > > Someone at some.domain [a.b.c.d] may be using SNMP to monitor your > mailserver for up and down status. > > > -----Original Message----- > > From: owner-freebsd-isp@FreeBSD.ORG > > [mailto:owner-freebsd-isp@FreeBSD.ORG]On Behalf Of Aaron Jackson > > Sent: Wednesday, December 13, 2000 4:23 PM > > To: mdickerson@officeonweb.net > > Cc: freebsd-isp@FreeBSD.ORG > > Subject: Re: sendmail NOQUEUE: Null connection from some.domain > > [a.b.c.d] > > > > > > Most likely Outlook is using a ms "feature" that is causing > this. I have > > seen this problem when clients were set to to secure connections but the > > server wasn't. > > > > Aaron > > > > On Wed, 13 Dec 2000 mdickerson@officeonweb.net wrote: > > > > > I apologize that this is more of a sendmail question but I > > thought someone > > > here might know this one. > > > > > > We have a client that is unable to send out mail. > > > He is connecting to the server (though not able to send mail) > but I find > > > this error in the logfile: > > > > > > Dec 13 08:53:51 ns1 sendmail[29411]: NOQUEUE: Null connection from > > > some.domain [a.b.c.d] > > > > > > This is a solo entry (no other related lines in the logfile). > > > > > > Eratta: > > > He uses Outlook. > > > He uses Qwest DSL (static ip: a.b.c.d). > > > We use a pop before smtp auth which works fine for our other clients. > > > > > > The sendmail site suggests: > > > "If it happens very often, it's either someone playing around > or it's a > > > network problem." > > > Unfortunately, this is only mildy illuminating :/. > > > > > > Does anyone know what is causing this or how to resolve this issue? > > > > > > TIA, > > > > > > Mike Dickerson > > > OfficeOnWeb.net > > > > > > > > > > > > > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > > > with "unsubscribe freebsd-isp" in the body of the message > > > > > > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > > with "unsubscribe freebsd-isp" in the body of the message > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-isp" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?NEBBIHDFEDCADAEBJEKAOEFFCJAA.jyoung>