Not recieving email, sender connect then disconnect

[Dagan McGregor]

Hi all,

I am wondering if anyone has any idea why some hosts are unable to
send me some email.

I have a new VPS setup at Rimu Hosting on Debian 6 (Squeeze), running
Postfix and Dovecot, and I've been able to send and recieve emails
through this fine.

However, it seems certain services aren't delivering email to me;
Twitter, Facebook, and NZOSS sites try to send confirmation emails that
never get delivered.

I see this in the /var/log/mail.log:

Jul 21 23:29:12 pro postfix/smtpd[23929]: connect from
ham-cannon.twitter.com[19
9.59.148.239]
Jul 21 23:29:13 pro postfix/smtpd[23929]: disconnect from
ham-cannon.twitter.com
[199.59.148.239]
Jul 21 23:32:33 pro postfix/anvil[23932]: statistics: max connection
rate 1/60s
for (smtp:199.59.148.239) at Jul 22 11:29:12
Jul 21 23:32:33 pro postfix/anvil[23932]: statistics: max connection
count 1 for
(smtp:199.59.148.239) at Jul 22 11:29:12
Jul 21 23:32:33 pro postfix/anvil[23932]: statistics: max cache size 1
at Jul 22
11:29:12
Jul 21 23:34:23 pro postfix/smtpd[23964]: connect from
121-73-240-178.broadband.
telstraclear.net[121.73.240.178]
Jul 21 23:34:23 pro postfix/smtpd[23964]: disconnect from
121-73-240-178.broadba
nd.telstraclear.net[121.73.240.178]
Jul 21 23:37:43 pro postfix/anvil[23967]: statistics: max connection
rate 1/60s
for (smtp:121.73.240.178) at Jul 22 11:34:23
Jul 21 23:37:43 pro postfix/anvil[23967]: statistics: max connection
count 1 for
(smtp:121.73.240.178) at Jul 22 11:34:23
Jul 21 23:37:43 pro postfix/anvil[23967]: statistics: max cache size 1
at Jul 22
11:34:23

The email addresses I have tried in the websites are setup as aliases,
and they work just fine if I email from work or another ISP. I just
tested them all sending emails from my work machine, and they all show
in the log being delivered and sent to the mailbox.

So I am not sure why the above log shows the connect and disconnect,
without an attempt at delivering email. As far as I am aware, there is a
PTR record for my mail server, but I haven't setup anything like an SPF
record yet.

Would it be best to look at setting up an SPF record and see if that
fixes the issue?

Dagan

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[Steve Holdoway]

Post by Dagan McGregor
Hi all,
I am wondering if anyone has any idea why some hosts are unable to
send me some email.
I have a new VPS setup at Rimu Hosting on Debian 6 (Squeeze), running
Postfix and Dovecot, and I've been able to send and recieve emails
through this fine.
However, it seems certain services aren't delivering email to me;
Twitter, Facebook, and NZOSS sites try to send confirmation emails that
never get delivered.
Jul 21 23:29:12 pro postfix/smtpd[23929]: connect from
ham-cannon.twitter.com[19
9.59.148.239]
Jul 21 23:29:13 pro postfix/smtpd[23929]: disconnect from
ham-cannon.twitter.com
[199.59.148.239]
Jul 21 23:32:33 pro postfix/anvil[23932]: statistics: max connection
rate 1/60s
for (smtp:199.59.148.239) at Jul 22 11:29:12
Jul 21 23:32:33 pro postfix/anvil[23932]: statistics: max connection
count 1 for
(smtp:199.59.148.239) at Jul 22 11:29:12
Jul 21 23:32:33 pro postfix/anvil[23932]: statistics: max cache size 1
at Jul 22
11:29:12
Jul 21 23:34:23 pro postfix/smtpd[23964]: connect from
121-73-240-178.broadband.
telstraclear.net[121.73.240.178]
Jul 21 23:34:23 pro postfix/smtpd[23964]: disconnect from
121-73-240-178.broadba
nd.telstraclear.net[121.73.240.178]
Jul 21 23:37:43 pro postfix/anvil[23967]: statistics: max connection
rate 1/60s
for (smtp:121.73.240.178) at Jul 22 11:34:23
Jul 21 23:37:43 pro postfix/anvil[23967]: statistics: max connection
count 1 for
(smtp:121.73.240.178) at Jul 22 11:34:23
Jul 21 23:37:43 pro postfix/anvil[23967]: statistics: max cache size 1
at Jul 22
11:34:23
The email addresses I have tried in the websites are setup as aliases,
and they work just fine if I email from work or another ISP. I just
tested them all sending emails from my work machine, and they all show
in the log being delivered and sent to the mailbox.
So I am not sure why the above log shows the connect and disconnect,
without an attempt at delivering email. As far as I am aware, there is a
PTR record for my mail server, but I haven't setup anything like an SPF
record yet.
Would it be best to look at setting up an SPF record and see if that
fixes the issue?
Dagan

SPF is really aimed at *sending* mail - defining the servers allowed to
do so for a given domain.

Sending mail would be best served through a smart host if Rimu offer one
( never used them so can't comment ) - that way you validate to rimu,
and rimu has validated to the rest of the world. This is much, much
easier than trying to validate your your own mail server with the big
boys... especially the exclmation mark boys.

It's surprising that a mail server connects/immediately disconnects. I'd
expect the sender to validate the recipient - rDNS, rbl, etc before even
attempting to connect rather than after having done so. Given the
timings, is there any possibility that the EHLO information returned is
lacking in some way?

Cheers,

Steve
--
Steve Holdoway <***@greengecko.co.nz>
http://www.greengecko.co.nz
MSN: ***@greengecko.co.nz
Skype: sholdowa


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[Dagan McGregor]

Post by Steve Holdoway
It's surprising that a mail server connects/immediately disconnects. I'd
expect the sender to validate the recipient - rDNS, rbl, etc before even
attempting to connect rather than after having done so. Given the
timings, is there any possibility that the EHLO information returned is
lacking in some way?

It was something in the connection, as it was requiring STARTTLS at
the initial connection, since I had that setting one level too high.

So I've tuned that down a bit, and it works receiving email again,
that I can see so far.

Thanks to Mark Foster for the tip :)

Cheers,
Dagan

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http://www.linux.net.nz/cgi-bin/mailman/listinfo/nzlug

[Robin Sheat]

Post by Dagan McGregor
However, it seems certain services aren't delivering email to me;
Twitter, Facebook, and NZOSS sites try to send confirmation emails that
never get delivered.

Turn debugging on in postfix, that should cause it to log the whole exchange
(iirc, it's been a while), which may give you a better idea about what's
happening and why.

Robin.