Bruce, I checked to see if we ended up on the public blackhole lists and we haven't. Wouldn't you expect that the mail server would drop the connection before accepting the MAIL FROM and prompting for the message? Or am I wrong?
John ----- Original Message ----- From: "Bruce Fyfe" <[EMAIL PROTECTED]> To: "MSWinNT Discussions" <[EMAIL PROTECTED]> Sent: Tuesday, May 14, 2002 12:33 PM Subject: RE: Low level TCP question > Another basic thing to look at is if they are using a blackhole list or > some other spam filter. Some firewalls will be too aggressive in > filtering mail that it considers originating from a spam site. > > Bruce Fyfe, Network Engineer > Lakeside Industries (www.lakesideind.com) > (425) 313-2600 > > > > -----Original Message----- > From: John P. Hoekstra [mailto:[EMAIL PROTECTED]] > Sent: Monday, May 13, 2002 10:48 PM > To: MSWinNT Discussions > Subject: Low level TCP question > > > Hi! > > I am having TCP/IP connectivity problems with seemingly random hosts on > the internet. However, the same hosts are very reliable in not talking > to our system. Unfortunately, some of these hosts belong to clients of > ours and we can't send them e-mail! > > Our system is Windows NT 4.0 SP6 with Exchange Server. > > The top level protocol is SMTP and the connection is timing out sending > the body of the mail message. For the hosts that fail to accept the > transmission, the pattern seems to be the same: > > The preliminaries of the SMTP protocol level always succeeds. Our system > sends multiple TCP packets containing the mail message with 1460 data > bytes in each packet. The remote host NAKs the first packet, so our > system retries 5 times The remote host either does not respond or sends > a FINISH packet > > I have netmon traces if anyone wants to see the gory details. > > John P. Hoekstra > [EMAIL PROTECTED] > Macatawa Computer Services, Inc. > 68-70 West 8th Street > Holland MI 49423-3159 > > > ------ > You are subscribed as [EMAIL PROTECTED] > Archives: http://www.swynk.com/sitesearch/search.asp > To unsubscribe send a blank email to %%email.unsub%% > > ------ > You are subscribed as [EMAIL PROTECTED] > Archives: http://www.swynk.com/sitesearch/search.asp > To unsubscribe send a blank email to %%email.unsub%% > > ------ You are subscribed as [email protected] Archives: http://www.swynk.com/sitesearch/search.asp To unsubscribe send a blank email to [EMAIL PROTECTED]
