On 8/27/05, Les Mikesell <lesmikesell@xxxxxxxxx> wrote: > On Sat, 2005-08-27 at 00:11, Jonathan Berry wrote: > > > Okay, a lot of ISPs now block port 25 out to anything other than their > > SMTP server. In some situations, it would be nice to circumvent this > > to get to another SMTP server if one is not available. > > If your ISP can't keep their mail server running, find another ISP. Actually, I mean not available as in not there, rather than not functional at times. And switching ISPs is not an option for someone on a University network (see other emails). > > So what I had > > though is to setup my FC4 linux box to listen for SMTP traffic on a > > non-standard port. > > How is anything else going to know to send to the non-standard port? It won't. I only care about mail clients being able to connect to it, and I can set them up that way. > If you are have multiple clients on a local LAN, you can have your > own mail server working on port 25 for local clients that won't be > blocked by the ISP, and configure this server to forward through > the ISP's server. Right. But the client I want to connect to it is not on the local LAN. It needs to come across the internet. > > Actually, I could just have my hardware router > > forward whatever port to 25 on the computer, so the non-standard port > > part should be easy. It would be nice to have a workable solution > > with as little as possible. Does anyone know of some way that I could > > maybe take any traffic to my server on my chosen high port and forward > > it along to my ISP's SMTP server on port 25? It sounds possible, but > > sketchy enough to where it might not be. Any ideas? > > It is easy to do this either with iptables or xinetd's 'redirect' > function, but I don't see the point here. If you have one email > client, point it to the ISP. If you want a local server, use > its smart_host feature to send everything outbound through the ISP. > > -- > Les Mikesell Obviously, I was not very clear on what I wanted to do. Sorry about that. Your two choices do not describe what I want. So can iptables or the xinetd redirect take traffic and send it back out the same interface to my ISP's SMTP server? That sounds like what I might want if so. Jonathan
