> Jay Lee wrote: >>Martijn Lievaart said: >> >> >>>[ off-list, my phone does not seem to understand mailinglists ] >>> >>> >Yes I understand. The reason I ask is that for IPv4, I am forced to >>> >use a external relay server with my ISP. However, for IPv6 it is not >>> >required. In fact, my ISPs relayserver does not support IPv6 at all. >>> >>>You could try to use your firewall to dnat all ipv4 connections to your >>>providers mailserver. It's a dirty trick, but I think it will work. >>> >>>F.I. Using iptables on linux (from memory, may contain mistakes): >>>iptables -A POSTROUTING -t nat -s <your-mailserver-ipv4> -p tcp --dport 25 >>>-j DNAT --to <isp-smarthost> >>> >>> >> >>I had tried something like this, the problem comes when your users try to >>do authenticated smtp with another mail server which would obviously fail >>to login to your ISP's smtp server. >> >>
> "Forced to use an external relay server" and "authenticated smtp with > another mail server" seem mutually exclusive to me anyhow. > There are other tricks though. I assume your users are local on the mail > server, otherwise the "-s" above takes care of the problem already and > it should just work. > 1) If on linux, use the owner match of iptables to only redirect > connections of the courier user. Obviously, you need to do this on the > machine running courier itself. Caveats: I don't know if the owner match > works in POSTROUTING. In that case you'll need to mark the connections > and redirect on the mark. I think you need to get the owner match from > patchomatic, which means patching your kernel. > 2) Move the courier to another machine, that does not need to send mail > other than through the relay. In that situation the firewall trick works > again. > HTH, > M4 The firewall and the courier box is the same. I also have users from outside too. But the iptables "-s <your-mailserver-ipv4> --dport 25" should work anyway, should it not, as the clients do not have the same source IP as the server? ~S ------------------------------------------------------- This SF.Net email is sponsored by: IntelliVIEW -- Interactive Reporting Tool for open source databases. Create drag-&-drop reports. Save time by over 75%! Publish reports on the web. Export to DOC, XLS, RTF, etc. Download a FREE copy at http://www.intelliview.com/go/osdn_nl _______________________________________________ courier-users mailing list [email protected] Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-users
