I checked for “connect from unknown” errors coming from the client IPs in
mail.log and I’m not seeing any. The only warning I see for one client is:
Jul 23 19:21:54 ravenviewhomes.com postfix/smtpd[61133]: warning:
fqdn_hidden[ip_hidden]: SASL PLAIN authentication failed:
Jul 23 19:22:39 ravenviewhomes.com postfix/smtpd[61179]: warning:
fqdn_hidden[ip_hidden]: SASL PLAIN authentication failed:
Jul 23 19:23:57 ravenviewhomes.com postfix/smtpd[61179]: warning:
fqdn_hidden[ip_hidden]: SASL PLAIN authentication failed:
Jul 23 19:24:44 ravenviewhomes.com postfix/smtpd[61179]: warning:
fqdn_hidden[ip_hidden]: SASL PLAIN authentication failed:
Jul 23 19:25:51 ravenviewhomes.com postfix/smtpd[61179]: warning:
fqdn_hidden[ip_hidden]: SASL PLAIN authentication failed:
Jul 23 19:25:58 ravenviewhomes.com postfix/smtpd[61179]: warning:
fqdn_hidden[ip_hidden]: SASL PLAIN authentication failed:
This appears to have been a temporary issue as the client had hundreds of
successful connection attempts today.
I had the clients attempt the telnet connect at least 10 times and I’m told
that they got the “220” response quickly each time. The slowness is not
consistent unfortunately. It seems to be intermittent. With many emails
sending immediately or after 5 seconds or so but a few taking 40-60 seconds.
Size of the email doesn’t seem to be a factor.
Thanks,
Chris McKinnon
On Jul 23, 2014, at 8:35 AM, Wietse Venema <wie...@porcupine.org> wrote:
McKinnon Chris:
> Hi Wietse,
>
> Concerning #1, I checked the mail.log and I'm seeing the following
> warnings (many times):
>
> postfix/smtpd[71979]: warning: hostname static.vdc.vn does not resolve to
> address 113.160.154.177
> postfix/smtpd[72386]: warning: hostname bamovil-181-135-42-61.une.net.co does
> not resolve to address 181.135.42.61: nodename nor servname provided, or not
> known
These two warnings are correct. The IP address resolves to a name,
but that name does not resolve at all, or it resolver to a different
IP address.
> postfix/smtpd[16896]: warning:
> nwk-txn-msbadger0202.apple.com.dbl.spamhaus.org: RBL lookup error: Host or
> domain name not found. Name service error for
> name=nwk-txn-msbadger0202.apple.com.dbl.spamhaus.org type=A: Host not found,
> try again
Sometimes spamhaus lookups fail.
> Concerning #2, I've asked my users to perform that test and I'll
> get back to you with the results. I did run:
>
> sudo cat /var/log/mail.log | grep -c "connect from unknown"
>
> And I'm seeing 4794 occurrences since July 11th.
Do you see "connect from unknown" for the client systems that
complain about delays?
When doing "telnet servername 25" from an affected client, how long
does it take for the server to respond with "220 servername ..."?
Wietse
