MultiDomain Email Question

[dimlark]

I know I've had to have read over the answer, and probably just don't understand it.

I'm trying to interest my employer in Linux-based solutions. I'd like to show them we can have a single mail server that can service multiple independant domains. NOT accepting emails for various domain and forwarding them to others, but having "jperson@domain1.com" and "jperson@domain2.com" that are completely different people, are both served by the same mail server, and do NOT have to have physical logins on the server. Everything I've looked at regarding virtual hosting, users and domains seems to only regard forwarding.

Is there a solution, a HOWTO I can refer to for this, or am I too new to linux and missing something?

Thanks!

[demian]

Maybe I don't see the complexity of the problem but serving different domains with one email server seems a rather trivial problem to me. Just about every email server I know is able to do that. There's no need for any virtual hosting or something like that.

Have you decided on what server you want to use? If not checkout exim. I'm using it on my network and can give you a hand with the initial setup.

[dimlark]

I've being working with Sendmail, but have looked at Postfix and QMail as well. The only mail users they appear to identify with are the ones that have an actual account on the box itself. The box (RH 8) has multiple domains that identify with its IP, but "jperson@<a_domain>" will only go to the one "jperson" that has an actual Linux login of "jperson", regardless of of which domain follows the "@". So, "jperson@domain1" and "jperson@domain2" go to the "jperson" Linux account.

Unless I use virtual domains, but then it only wants to forward it to another address.

Admiitedly I have NOT read the Sendmail book by O'Reilly from front to back. I looked in the index, but I must be looking under the wrong concept. I agree it must be trivial, and I must be looking right at it, but...

Looking on the web and HOWTOs for Sendmail, QMail and PostFix always seems to point to virtual users and domains, but that appears to only involve forward the email to another address or user.

Ultimately, I'd like to show that I can set up a Linux box to host multiple, independant, domains for email. Where the all email is stored on that one server for all of the unrelated domains until retrieval by the user, I do NOT have to have an acutal Linux account for ANY of these users, and hopefully some web-based software where a domain admin can be assigned to handle each domain without ever knowing about the others. ISPs do something like this don't they?

I was figuring something to do with LDAP and the mail spool (one per domain?), but I'm not finding it (though I've read enough to find out what they are). I really don't want more Windoze boxes cluttering up the office.

Thanks!

[demian]

Nooo. Not sendmail... I never really shyed away from a program because everybody bitched about how hard and confusing it is to set up. There's one exception and that's sendmail. I never touched that. Ever.

Now that you've described the problem a bit more detailed I can actually see that it'll be a bit more complicated. I thought you just want to deliver the mail to these different domains but you want to have the mailbox files on the server's hard drives, right? (Still sure that exim can handle it, though <cough>hint</cough&gt So even though you don't need to make everyone a unix user that gets mail on this system you have to tell your MTA by some means that there's gonna be a bunch of people that it'll be serving mails for even though /etc/passwd doesn't list them.

From the top of my head I only know how to do this for exim. So I guess I'm can't help you with this. If nobody else jumps in on this thread, I'd try the sendmail-user mailing list.

[dimlark]

I'm not married to SendMail. I'll consider anything that works and provides security.

I hadn't tried exim. I'm not against it by any means. If it works you use it. I'll check it out!

Thanks!

[vvx]

I think the problem is the pop3 server or imapd server is going to see a user trying to get mail from it with the user "foo" and if you have a user foo for both domain1 and domain2 there's going to have to be some way to keep them seperate. I also think most (all?) mail servers on nix are going to require the users actually have an account on the machine (they don't need a shell though, so set to /bin/false or something.)

So, what can you do to work around? It seems to me, many ISPs have logins that aren't just "User" for user@foo.com -- like, it might be "user-domain" or something. Then you just need to setup the aliases file to forward email based on which domain to the correct users (I'd imagine this could be scripted) -- so email sent to user@domain1 goes to user-domain1 on the machine.

Then again, I'm not an email server expert so maybe a much simpler method exists and I'm just unaware of it (for lack of need.)