On Fri, Apr 3, 2009 at 10:09 AM, Michel van Deventer <michel at 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 at attorneys.dyndns.net, but rather bob at attorneys.co.za. >> > > _______________________________________________ > CentOS mailing list > CentOS at 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. -- Kind Regards Rudi Ahlers