So are you saying that TZO.COM tracks their dynamic IP and instantly changes
the DNS record for the company to the current IP address? And TZO.COM sets
the TTL values on the DNS servers to be zero so that there is no caching
done? That is the only way I could see that this could work reliably. But
it seems like maybe you're also seeing problems with hosts that do
successfully look up the name.
I suppose the other thing to check is if there are problems with the inbound
path via DSL, could there be a hardware or other malfunction that makes some
sessions time out? Is there any pattern for which connecting hosts fail?
This posting is provided "AS IS" with no warranties, and confers no rights.
> Got interrupted by a power outage...
> Standard SMTP services - both inbound and outbound. Inbound senders send
> an SMTP server using the mail.domain.com name hosted by TZO.COM. Name
> resolution is not the problem as the various delivering SMTP servers can
> seen in the Sessions list.
> Reporting-MTA is always the delivering SMTP server.
> No POP, no authenticated TURN, no collection from secondary servers.
> > You say they have a dynamic IP, so I can assume that they're using
> > authenticated TURN from their ISP. Or are they using POP? The first
> > I would check is the NDRs: which server is generating them? If they're
> > DSNs, then the hostname of the server that generated it will be in <>s
> > the human readable part and will be the Reporting-MTA: in the machine
> > readable part. This will tell you which server can't talk to which
> > and is timing out. It makes some sense to me that there is a chance
> > the Exchange server isn't coming in and taking the mail before the
> > expiration time on the ISP server.
> > David
> > --
> > This posting is provided "AS IS" with no warranties, and confers no
> > > A client has Small Business Server 2000 (integrates Exchange 2000 and
> > ISA).
> > > OS is SP2; Exchange is now SP2; ISA is SP1.
> > > They had complaints of email returning to senders as NDR (various
> > > responses - but most boil down to time to deliver exceeded).
> > > I can open Exchange Admin console and see the sessions on the server;
> > > connections from the NDR'd ISP's remain open until the 600 seconds are
> > > stop, and restart almost immediately.
> > > Mail can flow in and out; though a few connections always seem to fail
> > > inbound.
> > > The client has a dynamic IP on a DSL connection; DNS is hosted by
> > > the data on the DNS servers always appears to be fine.
> > > Recent changes are the move from one domain name to another domain
> > > (external). I cannot for sure say that the problem came after the
> > > change, as the use of the service was limited prior to the new name
> > > set up.
> > > Microsoft has looked at the set-up and says it is OK.
> > > As I said - mail does move out, and most moves in. Failures seem to
> > > timeout related. I can see the sessions time out on the server. Even
> > short
> > > emails from my system to the server seem to take too long to complete.
> > > CPU spikes seem to be occurring. Trend OfficeScan MailScan service
> > > shut down - with no improvement.
> > > Can anyone suggest a path to follow for ultimate resolution to the
> > problem?
> > > Thanks
> > > Cal