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time for retry delivery

Printed From: LogSat Software
Category: Spam Filter ISP
Forum Name: Spam Filter ISP Support
Forum Description: General support for Spam Filter ISP
URL: http://www.logsat.com/spamfilter/forums/forum_posts.asp?TID=6781
Printed Date: 22 October 2017 at 11:49am


Topic: time for retry delivery
Posted By: AndrewD
Subject: time for retry delivery
Date Posted: 23 November 2009 at 8:00pm

My setup

Site1
Primary server hosting spamfilter and SQL
 
Site2
Secondary Spamfilter connecting to site1 SQL
 
Currently Site1 has lost internet (ISP Problem) for 48 hours. i have implemented a backup connection to site1 via a wireless service, and created entries in Site2 hosts file so email is now flowing in (and site2 has access to the SQL again), however i would have thought that as soon as this happened that there would have been a lot of email waiting at site2 to be delivered. But it doesnt seem to be coming through. Only email that is currently going through site 2 is being delivered.
 
Any idea's?



Replies:
Posted By: LogSat
Date Posted: 23 November 2009 at 11:00pm
I'm not sure we understood the exact scenario as far as which MX records are present in DNS for the domain(s) affected, and it with a wireless connection there were DNS changes in the IPs relative to the MX record servers. Can you provide more details on this? Please feel free to contact us via email at support at logsat.com if you'd like to keep the information private.

-------------
Roberto Franceschetti

http://www.logsat.com" rel="nofollow - LogSat Software

http://www.logsat.com/sfi-spam-filter.asp" rel="nofollow - Spam Filter ISP


Posted By: AndrewD
Date Posted: 23 November 2009 at 11:58pm

hi roberto,

will try to detail it for you.
we have spamfilter setup at two sites.
 
site 1
is the primary MX record for ntbm.com.au
houses spamfilter server with SQL and also a 2003 exchange server
 
Site 2
is the secondary mx record for ntbm.com.au
this has a second copy of spamfilter that looks at site1 for the sql database.
 
1. Site1 had a problem with its internet and went offline for 52 hours (just came back on about 30 minutes ago.
 
2. This morning i put in place a second internet feed but it had a dynamic ip.
 
3. Site2 normally forwards all good email to mail.ntbm.com.au on a shifted port. As the DNS will resolve this to the downed service, i placed a temporary entry into the hosts file of site2 to give it the temp ip for mail.ntbm.com.au
 
4. Restarted Spamfilter service
 
5. once i did this the sql link came back up and emails that came in were forwarded correctly.
however no emails that site2 received during the down time were forwarded to site1.
 
now that the normal service has been returned to site1 i removed the hosts file entries and restarted the spamfilter service, the emails that were backed up (approx 500) all flowed through, so why didnt they flow through as soon as it was able to send normally?
if i look at the log it says
"11/24/09 13:11:18:294 -- (35700) EMail from mailto:noreply@SenderDomain.com - noreply@SenderDomain.com to xyz mailto:xyz@ntbm.com.au - @ntbm.com.au --  was forwarded to mail.ntbm.com.au:{port number removed for the purposes of this thread}"
it is as though it had cached the IP for where this message had to go rather than realizing that the ip for mail.ntbm.com.au had changed.
 
Cheers
Will try to keep it in the forum as may help others ;)


Posted By: yapadu
Date Posted: 25 November 2009 at 8:20pm
When your primary link was down, were you able to telent into your secret port number?  Maybe there was a firewall or something blocking the connection to your exchange server when you were running on the backup line.

That would be the first thing I would check, confirm that you can

telnet mail.ntbm.com.au {port number}

I suspect it would not answer.


Posted By: LogSat
Date Posted: 25 November 2009 at 11:43pm
Originally posted by AndrewD AndrewD wrote:

now that the normal service has been returned to site1 i removed the hosts file entries and restarted the spamfilter service, the emails that were backed up (approx 500) all flowed through, so why didnt they flow through as soon as it was able to send normally?

if i look at the log it says
"11/24/09 13:11:18:294 -- (35700) EMail from mailto:noreply@SenderDomain.com - noreply@SenderDomain.com to xyz mailto:xyz@ntbm.com.au - @ntbm.com.au --  was forwarded to mail.ntbm.com.au:{port number removed for the purposes of this thread}"
it is as though it had cached the IP for where this message had to go rather than realizing that the ip for mail.ntbm.com.au had changed.

SpamFilter will forward emails to the destination SMTP server that is specified the "default destination SMTP" server settings, or, if a domain is configured to use a different customized destination SMTP server, they will be forwarded to that.
If the destination SMTP server is specified using an IP, SpamFilter will of course use that IP for delivery. If, as it appears here, a DNS entry is used, SpamFilter will attempt to have Windows resolve that host name (and thus use the host file if one was configured correctly).

The SpamFilter logs during the downtime may provide a clue as to why emails where not forwarded. The most likely causes are either (as yapadu mentioned already) connectivity problems with the new IP, or that the server running SpamFilter was unable to resolve the new name to the correct dynamic IP. In either case, yapadu is right on target in that the first thing to try is to run the "telnet mail.ntbm.com.au {port number}" telnet command from the server running SpamFilter to check that connectivity is available.


-------------
Roberto Franceschetti

http://www.logsat.com" rel="nofollow - LogSat Software

http://www.logsat.com/sfi-spam-filter.asp" rel="nofollow - Spam Filter ISP


Posted By: AndrewD
Date Posted: 26 November 2009 at 2:07am
I agree that the name must resolve correctly.
however what i am saying in short is.
 
spamfilter set to forward email to host.ntbm.com.au {shifted port}
mail.ntbm.com.au dns resolves to ###.###.###.001
This IP went offline.
configured in Hosts file an alternate/temporary IP address for host.ntbm.com.au
restarted the spamfilter service, as soon as i did this new incoming email was forwarded successfully to the alternate IP. Spamfilter made no attempt to send the backed up messages (according to the log file). At this point there is no reason why it shouldnt have been able to as it was quite happily sending any new message that arrived.
When service was restored to the orriginal IP address. i removed the hosts entry and restarted the spamfilter service.
now all of a sudden it tryed and successfully delivered all the backed up messages.
 
so the problem wasnt that the name could not resolve once the hosts entry was put in as then it wouldnt have been able to send the current emails.
 
at no stage did i alter the settings in spamfilter, the only thing i did was stop and start the service. and put entries in and out of the hosts file.
 
hope that clears it up a little for you.
 
if i get time i will try to replicate this on the weekend, to see if it is a consistent problem.
 
Cheers


Posted By: AndrewD
Date Posted: 26 November 2009 at 2:12am
Originally posted by yapadu yapadu wrote:

When your primary link was down, were you able to telent into your secret port number?  Maybe there was a firewall or something blocking the connection to your exchange server when you were running on the backup line.

That would be the first thing I would check, confirm that you can

telnet mail.ntbm.com.au {port number}

I suspect it would not answer.
 
sorry missed that entry. No i did not try telneting however i would guarantee it would have worked, as any new mail that was received in spamfilter was delivered to the host (at its new IP). as mail was flowing this was proof that the connection could be made and i see no point in telnetting to a known good server.



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