I have a portal with about 30 child portals attached, and they are all independent sites, with their own domains.  The email is set via the host and the most practical way I've done this and I believe other hsoting companies would work along the same lines, is to use the localhost/IP structure.

I use IP based relaying since we have a separte linux box setup and it handles the rules - including only accepting email in a certain format.

What this means is my clients can get get people to register on their site, and the mail is delivered with their own email address in the settings, but from my mail server.

By chance, most of these clients are hosted with me managing their mail, but, that shouldn't matter - the are using my mail settings, not theirs in the host account anyway. 

Does this give you any clarity?

Nina Meiers

Well your hosting company should provide you with some form of address to put into the server whether it's delivered directly from that box, or through another server. 

But perhaps if I word it this way -   When I set the mail settings up in the Host/settings.. Advanced / smtp settings - and tested it..   My clients can setup a hotmail address in their admistration section and still get notified of registrations.  Since the host settings is the implementor.. that's all.  It has nothing to do with the settings in the child/sub portals.

You aren't the host of the server, but I assume you're the host of the build.. that's why you should be able to contact the hosting provider and ask them whether you should be using localhost, 127.0.0.1 (these both allow for internal relaying - meaning - anything that tries to send from inside the machine is approved)  or do they have a secondary server setup where you need to put some mail configuration and password, or an IP address to get the connection happening.

For me - I use the IP based connection and that allows all my clients to send from the server. 

It's one of these things you often have to explain a few ways to get working.

Nina Meiers