On Tue, May 22, 2001 at 10:44:56PM +0100,
Darren Austin <darren@???> is thought to have said:
> I've had a look at this and found that grex.cyberspace.org does not send SMTP
> greeting (220) when you connect to the SMTP port, infact it doesn't output
> anything. However, if you telnet to the smtp on the host and manually enter a
> HELO line, it will start the usual SMTP delivery process, accept and deliver
> the mail without any problems.
>
> I believe this is what is causing the deferment issues because Exim is
> expecting (and waiting for) a 220 greeting from the remote host and isn't
> getting one.
>
> As I said above, I'm unsure if this is a bug in Exim or if cyberspace.org
> isn't following the RFC's by not outputting a 220 greeting, but either way,
> would it be worth looking into a configuration option which will set a timeout
> after which Exim will try to start to send an email even through it has not
> recieved a greeting message?
Well the greeting is a necessary part of the SMTP session per RFC 2821. If
you think about it, a mail server shouldn't try to send mail to another
until it is told it is ok to do so. The server may be too busy to handle
mail, or be having some other problem which would mean that you have no
guarantee that the mail was properly passed off to it.
Now as far as grex goes, I'd suspect you're having some firewall
interaction problem between your server and theirs. When I connect to port
25 from one of my servers which is behind no firewall the response is
instant:
220-grex.cyberspace.org Sendmail 8.6.13/8.6.12 ready at Tue, 22 May 2001 20:19:17 -0400
220 ESMTP spoken here
When I connect from another host which is behind a firewall, it also
responds but takes about 60 seconds to do so (probably timing out on
identd requests).
If you have a firewall in front of your mail server, check your firewall
logs to see what traffic you are receiving from grex or the network it's
on. Perhaps you are being a bit too agressive in your filtering.
Tabor
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Tabor J. Wells twells@???
Fsck It! Just another victim of the ambient morality
