Re: OT: Testing SMTP connections

On 17 July, 22:31, Catman <cat...@xxxxxxxxxxxxxxxxxxxxxxxx> wrote:
We have an application at work that receives email

We have an ongoing issue where exim reports that it has suffered a
timeout after connection to this app, and we're having real trouble
working out where this is.

If we run nagios SMTP check on the machine hosting the receiving app,
connecting to the receiving app, it sometimes reports timeouts. *But* if
you telnet to port 8825 (the listening port in this case) at the same
time the nagios checking code is reporting a timeout, it all works fine.

So that's not much use.

There are a number of apps out there that will send large volumes of
mail but that's not really practical for this app, plus not really what
I'm after as mail *throughput* is not at issue.

What I really want is something that will open multiple sequential
connections to port 8825 and report if it doesn't get an answer with n
milliseconds.

Any of you brain boxes have any suggestions?

Well I am not sure I qualify, however I have a few suggestions.

To test TCP port xxxx, you can use
PingPlotter. 1 month free then a small bit naggy - or cheap.

You can set the poll interval down to 1 sec. One thing I
worry about is leaving loads of half open connections
but it seems to not do this but it is worth checking for.

PingPlotter can also send normal or large pings.
PP is a really, really nice tool, nearly as nice as
BGN's, so I have heard him report.

You can also check smtp with telnet.

telnet x.x.x.x port.

If you search google for [smtp telnet test] you will
likely come across something.

e.g.
http://support.microsoft.com/kb/153119

One thing to be aware of is that current smtp
implementations support ehlo and old ones only
helo. RFC ... for more.

I am not going on for ages more here (well I
can't remember much of it off hand:) but come
back with more or - alternatively - just get me
in to figure it out:) I am probably cheap.

.

Relevant Pages

  • Re: OT: Testing SMTP connections
    ... If we run nagios SMTP check on the machine hosting the receiving app, ... it sometimes reports timeouts. ... you telnet to port 8825 at the same ... It times out after connection or while attempting to make connection. ...
    (uk.rec.motorcycles)
  • Re: Sending email
    ... The machines on which this app will be running ... : winsock on port 25). ... You can connect to an SMTP server locally which relays the ... that they can continue to listen for more connections on port 25. ...
    (microsoft.public.vb.general.discussion)
  • Re: Sending email
    ... The machines on which this app will be running ... : winsock on port 25). ... You can connect to an SMTP server locally which relays the ... that they can continue to listen for more connections on port 25. ...
    (microsoft.public.vb.general.discussion)
  • Re: Socket listener stops getting connections?
    ... the app stops ... > accepting new connections, even though it only has a few sockets open ... a listener on port 1803. ...
    (comp.unix.aix)
  • Re: Serial port question
    ... that just reads from the single serial port and writes to a database that ... multiple connections like this, but SQL CE doesn't. ... the GPS is connected to my PPC via Blue Tooth, ... Everything is going fine with the app. ...
    (microsoft.public.dotnet.framework.compactframework)
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