Topic: Server not receiving SMTP connections ... what are my debug options?

[julianop]

I'm  running 8.x, fully up to date, my domain, fixed IP, local mail service per the distro. I am not receiving incoming mail since having just switched ISP from a DSL provider to a broadband provider.

I believe my ISP is not routing mail to me, even though the domain and MX records look good on the ISP's configuration page and DNS lookups return appropriate MX information. My system had been working perfectly for several years, and I don't believe there is anything wrong with it now, so I am looking for debugging options to establish and then demonstrate to myself and my ISP that my side of the link is working.

Other facts:
The server runs in "single server" mode, on a local subnet through NAT to the outside world. The only thing I have changed at the server to support the change is the gateway IP address (I had both incoming connections feeding my LAN for a while, so the new connection needed a different GW address).

My local (LAN) email works perfectly: I can send outbound mail using the built-in transport, I can receive mail via fetchmail, and my users can view their mail (we use IMAP).

I have performed a port check using www.grc.com's "shieldsup!" port checker service. With the server down I get all ports reporting "stealth", and with the server up the service reports responses on ports 25, 80, 465, and 993, just as I would expect.

 I want to be able to see any inbound, WAN-side SMTP attempts to verify that the server is not rejecting connections. My question, then is "what debug options do I have to log incoming SMTP transactions ?"

[Stefano]

/var/log/qpsmtpd/current is the place

can you give us some details? domain, for example, will help us to check and report to you

[julianop]

OK great, Stefano, I'll look there, thanks.

It would be most helpful if you could report for me on if/how my server is responding.

Overnight I've have my ISP's Outlook system catching my mail for me so I don't lose it all. I've just disabled that redirect entry in the config, and the record change shows up as in sync. At this point any mail to my domain should come to my system.

My domain is "barnlea dot com", and mail to "jmobi" at that address should be accepted. Fire away, and thanks!

[Stefano]

I dropped you a mail

[julianop]

no l'ho recevuto, però...

Strange... I got the notification that you had posted, but via my provider's redirect system, which I had attempted to disable, but I did not receive your email. This is weird.

Just to minimize variables, would you be kind enough to send to jo397981 at that domain? That's the address registered at this forum.

Here's another item that confuses me... Per your suggestion I was watching /var/log/qpsmtpd/current (with "tail -Fn50 current") and noticed a relay attempt from dialtowin.com come in and get rejected, (as it should have been,of course). The only other entry is a repeated attempt at an anonymous address that doesn't progress to any real transfer. There are no entries related to successful transactions - not even yours. How could this be?

[Stefano]

done

[julianop]

First message arrived, eventually. I have responded privately.
For the benefit of the forum, Stefano check the MX record and found that mail is being diverted to my ISP's mail server system, which is expressly what I didn't ask them to do.

I'll try to get the domain record corrected, and see what happens then.

[julianop]

Update for Stefano, and anybody else who is so mind-bendingly bored as to be following this thread...

I found two things of interest:

1: my server is actually working correctly. I found this while watching the server's smtp transactions. I found a record of a message relay attempt to me at a domain I was managing a while ago, and for which my server had been backup MX. As soon as I added that domain to my server's list of domains, mail started coming in. That's wonderful: it means my server is working as I had always thought, and I can't ask you fine folks to do anything more for me. However, that said, for the general interest of the craft:

2: As I see it the domain record table on my ISP's configuration page looks incorrect; It shows an MX record like this:
(obviously my actual domain is replaced here, in order to minimize misuse)

MX   mail.mydomain.com.   5 mail.mydomain.com.   3600

while the ISP's redirect line (where they could be backup for my mail) is here:
MX   mydomain.com.   10 mail.s1154932-210036.my_isp's_domain.net.   3600

Clearly the first record is wrong: "mail.mydomain.com" in the leftmost field would have to be a subdomain, and it's not - it's my actual mail server name declared in an accompanying (and correct) A record.

Presumably if my ISP tries to publish this entry other, saner DNS servers will reject that, which is why there is still no valid MX record for my name out in the big Internet world.

Am I interpreting this correctly?

[janet]

julianop

You need the redirect deleted.
You do not need a MX record, & you do not need a backup MX record.
As long as your main SME server domain is configured in external DNS records eg
www.yourdomain.com
then SME server will receive mail for that domain from other mail servers.

Refer to the FAQ (Email section) & the online Manual Appendix, links at top of forum.
In particular http://wiki.contribs.org/SME_Server:Documentation:FAQ:Section04#Secondary.2FBackup_Mail_Server_Considerations

[Stefano]

julianop

You need the redirect deleted.
You do not need a MX record, & you do not need a backup MX record.
As long as your main SME server domain is configured in external DNS records eg
www.yourdomain.com
then SME server will receive mail for that domain from other mail servers.

Refer to the FAQ (Email section) & the online Manual Appendix, links at top of forum.
In particular http://wiki.contribs.org/SME_Server:Documentation:FAQ:Section04#Secondary.2FBackup_Mail_Server_Considerations

well, there are cases you don't want such a setup

I have some customers that have their websites oin remote/external hosting and mail on their internal SME..
so an appropriate external DNS setup is mandatory.

just my 2€c

[guest22]

well, there are cases you don't want such a setup

I have some customers that have their websites oin remote/external hosting and mail on their internal SME..
so an appropriate external DNS setup is mandatory.

just my 2€c

That would be a good addition to the wiki Stefano...

[janet]

Stefano

well, there are cases you don't want such a setup.....so an appropriate external DNS setup is mandatory.

Of course, but in this thread we are talking about the specific case of julianop.

[julianop]

Thanks for the replies, folks..

Actually Janet, in this case I did need an MX record, because the IP of the mail server is not the same as the IP for the domain :- )

My ISP handles the web part of my domain (or will do, when I get around to writing a web page!), but I handle the mail on my own server, which is behind my NAT wall, port-mapped to my fixed IP.

It turned out that the MX record was indeed incorrectly specified in the configuration page for my domain:

MX   mail.barnlea.com.   5 mail.barnlea.com.   3600

should have read

MX   barnlea.com.   5 mail.barnlea.com.   3600

Once we corrected that (the editor is brain-dead, but we found out how to get around the problem) mail started to come down the pipe.

Now I have mail flowing, I can complete my desired setup by using my ISP as my backup mail server, as I've already corrected my users on their Outlook system. All I need to do is to set up a fetchmail cron to pull down anything that sits up there in the backup server.

Thanks again for your help