On Wed, 13 Mar 2002, Phil Pennock wrote:
> 209.151.233.24, which ultimately reverses to the lovely little hostname
> "fix.your.open.relay.or.die.net", has something listening on port 25
> which never issues an SMTP banner.
It did when I tried it:
$ telnet 209.151.233.24 25
Trying 209.151.233.24...
Connected to 209.151.233.24.
Escape character is '^]'.
220 fix.your.open.relay.or.die.net ESMTP
However, it took a long time to respond.
> The Exim delivery process never times out on this.
I've just done tests with Exim 4. In straightforward tests, it does time
out if no banner is received. Also if the first line only of a multiline
response is received.
AFAICS, after the
> connection is opened (proceeds normally), the command_timeout should
> apply to waiting for the banner. Documented default is 5 mins. I'm
> seeing processes which are still waiting for much longer. The only one
> which I haven't yet killed has been waiting 24 mins (age of -J file).
It seems to wait (deliberately?) a very long time before answering each
command. Maybe that is what you were seeing?
> What would happen if a remote server gave a "220-" line every four
> minutes? [209.151.233.24] is currently not reachable, or I'd check
> there. ;^)
Your server would suffer... eventually Exim's command line buffer would
be full, and it would barf.
Philip
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.
