Appreciate the feedback from everyone. I just figured out the problem. We have an internet filter appliance that is in-line right before the firewall. Servers/Network--->Filter Appliance--->Firewall--->Internet
The filter was changed the other day with a setting that blocked all non-HTTP traffic to unknown IP addresses, so the box was effectively blocking all email outbound and dropping the smtp sessions. Turning off that rule on the filter allowed email to flow again. Fun. Thanks for the tips. J Original Message: ----------------- From: Bob Smith b...@neconsulting.net Date: Mon, 4 Oct 2010 12:54:26 -0400 To: ntsysadmin@lyris.sunbelt-software.com, pmaglin...@scvl.com Subject: Re: outbound smtp broke (connection to host lost) Are you using a mail services (postini) to check your outbound mail, if so is your account ok with them, have you tested from outside using a site like http://mxtoolbox.com HTH, Bob Smith -------------------------------------------------- From: <jesse-r...@wi.rr.com> Sent: Monday, October 04, 2010 10:50 AM To: "NT System Admin Issues" <ntsysadmin@lyris.sunbelt-software.com> Cc: "Maglinger, Paul" <pmaglin...@scvl.com> Subject: outbound smtp broke (connection to host lost) > Stuck on this one. > > (1) Exch 2003 server that is my SMTP outbound connector > (1) Exch 2007 server that only hosts mailboxes > > For some reason my Exch 2003 server stopped sending outbound emails on > Friday. All messages are getting stuck in the queue and show "the > connection was dropped by the remote host" when I look at the queue. I > made sure that our outgoing IP (24.56.73.162) is NOT on spamhaus or other > blacklist. So everything looks good there. > > If I try telneting from the Exch 2003 server, it opens successfully to a > destination mail server, but as soon as I try typing "H" (for Helo), it > disconnects with a "connection to host lost" message in the command > prompt. > > I also, just for test purposes, tried telneting from the Exch 2007 server > (even though it does NOT deliver outbound mail at this time, it only > forwards stuff to the Exch 2003 smtp connector), to various mail servers > and the SAME thing happens from the 2007 server. I can telnet, but after > typing "H", the connection to host is lost. > > What's more interesting is, on my local machine, I CAN telnet into any > internet mail server and typing "H" does NOT drop the connection at all. > > I'm doubting it's a firewall issue because telnet isnt blocking the telnet > session from Exch 2003. I'm doubting we're on spamhaus, etc. (checked the > spamhaus.org website to be sure), and my ISP says it's not them dropping > the connection.. So.... > > Any ideas? > Thanks. > > > > > ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ > ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ > > --- > To manage subscriptions click here: > http://lyris.sunbelt-software.com/read/my_forums/ > or send an email to listmana...@lyris.sunbeltsoftware.com > with the body: unsubscribe ntsysadmin ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to listmana...@lyris.sunbeltsoftware.com with the body: unsubscribe ntsysadmin -------------------------------------------------------------------- mail2web LIVE Free email based on Microsoft® Exchange technology - http://link.mail2web.com/LIVE ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to listmana...@lyris.sunbeltsoftware.com with the body: unsubscribe ntsysadmin
