nanog mailing list archives

Re: SMTP no-such-user issues


From: Steve Bertrand <steve () ibctech ca>
Date: Tue, 17 Jun 2008 09:20:12 -0400

Steve Bertrand wrote:
Frank Bulk - iNAME wrote:
Once you've performed a full capture on port 25, Wireshark does a nice job
of providing an option to extract the relevant conversation by
right-clicking on just one packet in that conversation and choosing
something called "Follow the TCP stream", I believe.

Ok. I've never captured in tcpdump and then imported into Wireshark before, but I'll do some tests, scp the file to my Windows workstation, then follow the stream.

Once I ensure I get a clean stream, I'll post the results.

As I research the documentation on the how-to specifics on capturing with tcpdump in a format that is Wireshark compatible, is there anyone here that could perform a simple test against their own domain email system, that can confirm or deny what I have been witnessing?

If it can be confirmed that either A) my end is broken, or B) a remote end is broken, I will be content, and can continue with other work.

My mind will rest at ease if someone, with known bounce-no-mbox enabled, can:

- provide me off list (or test for themselves from a remote location) a list of valid, and invalid recipients within their own domain's email infrastructure. It doesn't even matter if you specify which are valid and which ones are not

- create a temporary account on Hotmail (or from a sympatico.ca email address, using whatever outbound servers they specify) send a message to the same recipients as requested above.

- in the case that you don't want to provide the addresses, and want to test internally, inform me of the overall result

- in the case that I receive the addresses to test from my location, provide me with the results of the Hotmail test so I can compare results

If this is happening to other ops along with myself, I can justify it to my users, and I can justify it in my own mind. If this is a locale specific issue to my own network, then I need to know that, as I obviously have work to do.

Thanks to everyone again.

Steve


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