Hi all,
I hope this isn't too OT, but since I use a CentOS5.2 + Exim mail server (which is hosted in one of our data centres) I don't think it should be.
On of our clients use an MS Exchange 2003 SBS server, with exchange for their internal email. We provide them with a domain, ADSL (which uses dynamic DNS) and POP3 email. They don't have an spam filter program on the exchange server itself due to costs, so I have setup each user on the Exim server, which runs ASSPX for anti-virus / spam filter / etc. Then I setup the SBS 2003 server to pull the email via POP3, but this doesn't seem to work too well, cause the exchange server doesn't always download the POP3 email, and then the users often sit without email until I go there to manually download the mail again.
I have tried changing the MX record to point to their DynDNS address, and it works well, but then they get a lot of spam. And the cost of a server-side spam solution is just too expensive, and they also pay for the bandwidth uses when spam comes in. So, I moved their MX record back to the Linux server. But now I sit with the problem of the POP3 connector failing from time to time.
So, I would like to know, is there a way to "push" (not forward) mail from the Linux server, after it has arrived and spam been blocked, to another domain, but with the same email address? i.e. the domain in question is attorneys.co.za and I've setup attorneys.dyndns.net as the dynamic domain, but the exchange serves email for attorneys.co.za Forwarding email doesn't work, since there's no such user as bob@attorneys.dyndns.net, but rather bob@attorneys.co.za.
Hi,
my solution to this kind of problem is the following : Set up a relay mailserver (in my case Postfix) which accepts mail (and has the MX record for the domain) for the domain but has no mailboxes. Postfix takes care of spamblocking (dnsbl and spamfilter ). In Postfix I use a transport table to relay the mail to the Exchange/Whatever mailserver, that can also be on a nonstandard port (in my case port 2525). Delivering to a dyndns host is really easy, Dyndns uses a short ttl for the hostname (something like 3 minutes ?). I set up a nameserver record which let a 'fixed' name (like mail.domain.nl) point to the dyndns name using CNAME. mail.domain.nl. IN CNAME mailhost.dyndns.org
Sending the mail to the dyndns hostname directly without the nameserver trick is also possible.
Using a non-standard port is to bypass SMTP limits from the provider and to make (almost) sure your mail doesn't get delivered to a mailserver of someone else ;)
Regards,
Michel
On Fri, 2009-04-03 at 09:40 +0200, Rudi Ahlers wrote:
Hi all,
I hope this isn't too OT, but since I use a CentOS5.2 + Exim mail server (which is hosted in one of our data centres) I don't think it should be.
On of our clients use an MS Exchange 2003 SBS server, with exchange for their internal email. We provide them with a domain, ADSL (which uses dynamic DNS) and POP3 email. They don't have an spam filter program on the exchange server itself due to costs, so I have setup each user on the Exim server, which runs ASSPX for anti-virus / spam filter / etc. Then I setup the SBS 2003 server to pull the email via POP3, but this doesn't seem to work too well, cause the exchange server doesn't always download the POP3 email, and then the users often sit without email until I go there to manually download the mail again.
I have tried changing the MX record to point to their DynDNS address, and it works well, but then they get a lot of spam. And the cost of a server-side spam solution is just too expensive, and they also pay for the bandwidth uses when spam comes in. So, I moved their MX record back to the Linux server. But now I sit with the problem of the POP3 connector failing from time to time.
So, I would like to know, is there a way to "push" (not forward) mail from the Linux server, after it has arrived and spam been blocked, to another domain, but with the same email address? i.e. the domain in question is attorneys.co.za and I've setup attorneys.dyndns.net as the dynamic domain, but the exchange serves email for attorneys.co.za Forwarding email doesn't work, since there's no such user as bob@attorneys.dyndns.net, but rather bob@attorneys.co.za.
On Fri, Apr 3, 2009 at 10:09 AM, Michel van Deventer michel@van.deventer.cx wrote:
Hi,
my solution to this kind of problem is the following : Set up a relay mailserver (in my case Postfix) which accepts mail (and has the MX record for the domain) for the domain but has no mailboxes. Postfix takes care of spamblocking (dnsbl and spamfilter ). In Postfix I use a transport table to relay the mail to the Exchange/Whatever mailserver, that can also be on a nonstandard port (in my case port 2525). Delivering to a dyndns host is really easy, Dyndns uses a short ttl for the hostname (something like 3 minutes ?). I set up a nameserver record which let a 'fixed' name (like mail.domain.nl) point to the dyndns name using CNAME. mail.domain.nl. IN CNAME mailhost.dyndns.org
Sending the mail to the dyndns hostname directly without the nameserver trick is also possible.
Using a non-standard port is to bypass SMTP limits from the provider and to make (almost) sure your mail doesn't get delivered to a mailserver of someone else ;)
Regards,
Michel
On Fri, 2009-04-03 at 09:40 +0200, Rudi Ahlers wrote:
Hi all,
I hope this isn't too OT, but since I use a CentOS5.2 + Exim mail server (which is hosted in one of our data centres) I don't think it should be.
On of our clients use an MS Exchange 2003 SBS server, with exchange for their internal email. We provide them with a domain, ADSL (which uses dynamic DNS) and POP3 email. They don't have an spam filter program on the exchange server itself due to costs, so I have setup each user on the Exim server, which runs ASSPX for anti-virus / spam filter / etc. Then I setup the SBS 2003 server to pull the email via POP3, but this doesn't seem to work too well, cause the exchange server doesn't always download the POP3 email, and then the users often sit without email until I go there to manually download the mail again.
I have tried changing the MX record to point to their DynDNS address, and it works well, but then they get a lot of spam. And the cost of a server-side spam solution is just too expensive, and they also pay for the bandwidth uses when spam comes in. So, I moved their MX record back to the Linux server. But now I sit with the problem of the POP3 connector failing from time to time.
So, I would like to know, is there a way to "push" (not forward) mail from the Linux server, after it has arrived and spam been blocked, to another domain, but with the same email address? i.e. the domain in question is attorneys.co.za and I've setup attorneys.dyndns.net as the dynamic domain, but the exchange serves email for attorneys.co.za Forwarding email doesn't work, since there's no such user as bob@attorneys.dyndns.net, but rather bob@attorneys.co.za.
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Thanx Michel, but how todo this on Exim? :) lemme see if I can find similar scenarios for Exim, now that I know what to look for.
Rudi Ahlers wrote:
Thanx Michel, but how todo this on Exim? :) lemme see if I can find similar scenarios for Exim, now that I know what to look for.
consider trimming your posts ?
On Fri, 03 Apr 2009 11:13:50 +0200, Rudi Ahlers wrote:
Thanx Michel, but how todo this on Exim? :) lemme see if I can find similar scenarios for Exim, now that I know what to look for.
basically a manualroute router like this could do
smart_host:
driver = manualroute domains = blabla transport = remote_smtp route_list = * name_of_exchange_server ignore_target_hosts = 0.0.0.0 : 127.0.0.0/8 self = defer
and a transport referred to
remote_smtp: driver = smtp
see also at http://www.exim.org/exim-html-current/doc/html/spec_html/ ch20.html
when you are responsible for an exim server i recommend reading the exim manual. although, there is a whole lot to read, i know. no offends please ;-)
On Sat, Apr 4, 2009 at 12:56 PM, Markus Falb markus.falb@fasel.at wrote:
On Fri, 03 Apr 2009 11:13:50 +0200, Rudi Ahlers wrote:
Thanx Michel, but how todo this on Exim? :) lemme see if I can find similar scenarios for Exim, now that I know what to look for.
basically a manualroute router like this could do
smart_host:
driver = manualroute domains = blabla transport = remote_smtp route_list = * name_of_exchange_server ignore_target_hosts = 0.0.0.0 : 127.0.0.0/8 self = defer
and a transport referred to
remote_smtp: driver = smtp
see also at http://www.exim.org/exim-html-current/doc/html/spec_html/ ch20.html
when you are responsible for an exim server i recommend reading the exim manual. although, there is a whole lot to read, i know. no offends please ;-)
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Thanx, no offense taken :)
Unfortunately I don't have the time to read through every piece of software I use's manual. And if do,I often don't take in 100% of the manual. I'd rather focus on learning the important things that I need to know.
I'll give this router option a go and see how it works.
on 4-3-2009 12:40 AM Rudi Ahlers spake the following:
Hi all,
I hope this isn't too OT, but since I use a CentOS5.2 + Exim mail server (which is hosted in one of our data centres) I don't think it should be.
On of our clients use an MS Exchange 2003 SBS server, with exchange for their internal email. We provide them with a domain, ADSL (which uses dynamic DNS) and POP3 email. They don't have an spam filter program on the exchange server itself due to costs, so I have setup each user on the Exim server, which runs ASSPX for anti-virus / spam filter / etc. Then I setup the SBS 2003 server to pull the email via POP3, but this doesn't seem to work too well, cause the exchange server doesn't always download the POP3 email, and then the users often sit without email until I go there to manually download the mail again.
I have tried changing the MX record to point to their DynDNS address, and it works well, but then they get a lot of spam. And the cost of a server-side spam solution is just too expensive, and they also pay for the bandwidth uses when spam comes in. So, I moved their MX record back to the Linux server. But now I sit with the problem of the POP3 connector failing from time to time.
So, I would like to know, is there a way to "push" (not forward) mail from the Linux server, after it has arrived and spam been blocked, to another domain, but with the same email address? i.e. the domain in question is attorneys.co.za and I've setup attorneys.dyndns.net as the dynamic domain, but the exchange serves email for attorneys.co.za Forwarding email doesn't work, since there's no such user as bob@attorneys.dyndns.net, but rather bob-cXiXO26w8qUnikiFv2/1gg@public.gmane.org
I use MailScanner. It can be set up on your gateway, integrates with exim very well, and can virus scan as well as spam scan.
www.mailscanner.info and for howtos
http://wiki.mailscanner.info/doku.php?id=&idx=documentation:configuratio...
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Karanbir Singh -
Markus Falb -
Michel van Deventer -
Rudi Ahlers -
Scott Silva