I forgot to CC the list. Sorry, here is the reply.
----- Original Message -----
From: "Willie Viljoen" <will@???>
To: "KARPATI Andras" <karpati@???>
Sent: Tuesday, November 11, 2003 1:28 PM
Subject: Re: virtual domains
> ----- Original Message -----
> From: "KARPATI Andras" <karpati@???>
> To: "'Willie Viljoen'" <will@???>
> Sent: Tuesday, November 11, 2003 12:25 PM
> Subject: virtual domains
>
>
> > On this server we have several domains. My problem is that I can't
> > separate the domains. For example I have the domain zenevilag.net and
> > tudas.com. Both should have an e-mail address like info@???
> > and info@???. Right now, if someone sends an e-mail to the info@
> > it all goes to the same place without separating them by its domains.
> >
> > What we would like to do, is to separate the domians deliver the
> > info@??? and info@??? to different accounts...
> >
> > Can anyone suggest me a solution how to do this?
>
> This is a limitation in UNIX, not Exim, but it's not that hard to get
> around. What you want to do is configure Exim to read seperate alias files
> for each domain, and deliver to the different users. The example I will
give
> you here uses a simple, but effective solution. Some prefer using a
database
> to do these lookups, and that is more efficient, but might require
> installation of RDBMS software, and rebuilding Exim. This can work right
> away. It is a lot of work, but fairly easy to do. First off, you want to
get
> your domain lists right, especially if you are going to be hosting a
number
> of these domains.
>
> The best way to do this is to have the domains listed in a line delimited
> plain text file. Most systems have a directory for storing mail related
> configuraiton files. For my examples I will use the BSD convention of
using
> /etc/mail. First, create a directory to hold virtual domain information, I
> use /etc/mail/virtual. Now, put a file in this directory, I will call it
> domainlist. In /etc/mail/virtual/domainlist, list your domains like this:
>
> domain1.net
> domain2.net
> domain3.com
>
> Now, you will want to include this in your Exim configuration. In the
> primary configuration are, set up the domainlists to look like this:
>
> domainlist local_domains_virtual = /etc/mail/virtual/domainlist
> domainlist local_domains = yourdomain.com :
> +local_domains_virtual
>
> This configures Exim to always check that file to see if a domain is one
of
> your local domains, and to accept primeraly for yourdomain.com. This also
> helps because there's no need to reload Exim after adding a domain. The
> update to the file will be effective right away, making it easier if you
> want to write scripts to add users automatically.
>
> Now comes the fun part. What you want to do is add a router which checks
the
> +local_domains_virtual domainlist, and read seperate alias files (if they
> exist) for a domain which matches this list. This router should look like
> the one below, and should be place very high in your router list, after
> virus scanning, smarthost, etc:
>
> # This router redirects addresses in virtual domains to different local
> users for later
> # local delivery.
>
> virtual_domain:
> driver = redirect
> allow_fail
> allow_defer
> domains = +local_domains_virtual
> data = ${lookup{$local_part}lsearch*{/etc/mail/virtual/$domain}}
> user = mailnull
> group = mail
> file_transport = address_file
> pipe_transport = address_pipe
> no_more
>
> By now it should start to become obvious how we are going to route the
> domain. The router is only tried if the domain is in the
> +local_domains_virtual list. Then, the lookup is done inside a file
> referenced as /etc/mail/virtuak/$domain. $domain is expanded to the domain
> part of the recipient address. This means that for an e-mail sent to
> johndoe@???, $domain expands to anonymous.com.
>
> In the case of Mr. Doe. The search would look inside
> /etc/mail/virtual/anonymous.com to find where to redirect his mail. Thus,
> for each domain, you want to have a file in /etc/mail/virtual/ with the
file
> name corresponding to the domain.
>
> It should also be noted that I have used the lsearch* lookup type above.
> This allows for * to be expanded to match any local part in the file,
> allowing for default addresses and the like. Here is a sample of the files
> which I will call "domain alias files".
>
> johndoe: anon-john
> janedoe: anon-jane
> peter: anon-pete, peter@???
>
> From here it should be clear that these files use a format similar to a
> normal alias file (like /etc/aliases). Thus, mail for
johndoe@???
> would be delivered to the anon-john user on the server. The same for Jane
> Doe. Mail for peter@??? will be delivered to the anon-pete user,
> and his other address peter@???. This provides a simple and easy
to
> configure way to host multiple domains.
>
> The only thing that might annoy you is that you will have to give your
users
> usernames like anon-john. This can be worked around in several ways. The
> easiest way I have found (for users that only check POP3 mailboxes that
is)
> is provided by the Solid POP3D (also known as spop3d) daemon. Several
other
> POP3 servers might do the same thing, but I have found spop3d the easiest
to
> set up.
>
> Firstly, for this method to work, you will have to change the format of
your
> domain alias files, removing all white spaces. Also, you will only be able
> to list one local user. No local or remote aliases, thus:
>
> johndoe:anon-john
> janedoe:anon-jane
> peter:anon-pete
>
> Once this is all set up, you can set up your spop3d.conf to look like
this:
>
> <Global>
> AllowNonIP true
> </Global>
>
> <VirtualHost yourdomain.com>
> MailDropName /var/mail/%s
> MailDropType mailbox
> DoMapping false
> </VirtualHost>
>
> <VirtualHost anonymous.com>
> MailDropName /var/mail/%m
> MailDropType mailbox
> UserMapFile /etc/mail/virtual/anonymous.com
> DoMapping true
> </VirtualHost>
>
> <VirtualHost customer2.com>
> MailDropName /var/mail/%m
> MailDropType mailbox
> UserMapFile /etc/mail/virtual/customer2.com
> DoMapping true
> </VirtualHost>
>
> Note, the first setting is for your own domain, but should never really be
> used by clients. It should be there anyway though. With these settings,
when
> a user logs in as username, or username@???, mail for username
is
> checked on your server. When a user logs in with username@???,
> things happen abit differently. Users are then mapped from information in
> the domain alias files. In the case of a user loggin in with username
> johndoe@???, mapping in /etc/mail/virtual/anonymous.com would
> point johndoe to anon-john. The daemon then checks mail for the anon-john
> system user and delivers it to the client.
>
> It should now become obvious that with this setup, a user loggin in as
> anon-john and john@??? will produce the same effect.
>
> If you have some extra IP addresses available, you can also go for a more
> sophisticated configuration. I use private IPs here. You will probably
need
> routable IP addresses, unless all customers are in your LAN. Here is a
> sample spop3d.conf:
>
> <Global>
> AllowNonIP true
> </Global>
>
> <VirtualHost 10.0.0.37 yourdomain.com>
> MailDropName /var/mail/%s
> MailDropType mailbox
> DoMapping false
> </VirtualHost>
>
> <VirtualHost 10.0.0.44 anonymous.com>
> MailDropName /var/mail/%m
> MailDropType mailbox
> UserMapFile /etc/mail/virtual/anonymous.com
> DoMapping true
> </VirtualHost>
>
> <VirtualHost 10.0.0.45 example.com>
> MailDropName /var/mail/%m
> MailDropType mailbox
> UserMapFile /etc/mail/virtual/example.com
> DoMapping true
> </VirtualHost>
>
> In this case, the first virtualhost is still your domain, but it WILL be
> used. Note that the server users check for your domain should correspond
to
> the IP address in this virtualhost line. For your domain, things are
> straight forward. Clients connect to 10.0.0.37, and log in with username.
> The mail for username on your system is checked and delivered. Simple.
>
> For the virtual domains, it is just as simple, but slightly different. A
> client connects to 10.0.0.44 and logs in with username johndoe. The spop3d
> server now checks its configuration file and maps 10.0.0.44 to be the POP3
> server address for anonymous.com. It checks the anonymous.com domain alias
> file and maps johndoe to anon-john, and delivers the anon-john mail to the
> client.
>
> Thus, in this more complex, one IP address per domain setup. A login to
> 10.0.0.34 with username anon-john and a login to 10.0.0.44 with username
> johndoe would create the same effect.
>
> This could be very handy for doing something like this. I use DNS zone
file
> format as an example, you would need to do this properly on DNS servers in
> the real world, with real addresses:
>
> pop3.yourdomain.com. IN A 10.0.0.34
> pop3.anonymous.com. IN A 10.0.0.44
> pop3.noname.com. IN A 10.0.0.45
>
> I hope all of this helps.
>
> Will
>
