Many domains on one exchange 2003

check https://www.experts-exchange.com/questions/22754777/Adding-additional-SMTP-domain-to-existing-Exchange-system.html

Check this article: http://support.microsoft.com/kb/268838
This may also help: http:Q_21208419.html

If by 'domain' you are referring to a Windows AD domain rather than an SMTP domain, then the answer is also yes.

An Exchange 2003 server can host a mailbox for any user account in any domain which is in the same forest. You would need to configure a recipient update policy for the user account domain, but this is quite simple to do.

An Exchange 2003 server can host a mailbox for user accounts in domains in different forests, but the user provisioning process must create a matching user account in the Exchange domain. When the user in the remote domain loads Outlook or goes to OWA, they will be prompted for a username/password with which to authenticate.

I meant by domain, is that i have test.com and mama.org (mama.org is not a sub domain) and i want one exchange server to host both, and also i need users of test.com to send messages using test.com address and the other address is the same, i read about OU, can i do it using OU and if yes, can user of test.com login to a specific OU? i guess not, please correct me if i'm wrong, also do i have to change anything in the DNS?
i read lots of articles and no one descripes it like 1. do this and that 2. do this and that 3. ...

you need to first configure the exchange server to accept emails for test.com and mama.org
once that is done, you can configure recipient policies accordingly. the policies don't work on OU membership. you will need to filter the policy on a common attribute

Do i need to change anything in the AD?
test.com and mama.org are currently working and receiving messages but they are on separate machines, the reason why i want to join the two on a single machine is that mama.org is serving 3 users only

no.
are you hosting your own MX records or is your ISP doing that for you?

I'm hosting the MX records

do you have an MX record in your domain for both the domains?

no, each domain is on a seperate machine at the moment

so what should be my first step in resolving this matter?

how are the domains hosted on seperate servers?

yes

how are the domains hosted?

Please explain more?

you mentioned earlier that each domain is hosted on a seperate server. i want to know how are the domains hosted on seperate servers.

seperate servers and seperate networks, i need to retire one server and have both domains on one machine

ok, so two seperate smtp domains on two seperate exchange servers which are in different exchange orginazations. is that correct?

yes

ok. so the steps would be
modify the Mx record of the new domain so that it points to the new exchange server that will be hosting it
configure exchange to accept mail for the new domain
the replication of MX record changes can take upto 48 hours

Configuring exchange to accept new mail means add a new recipient policy?
and what will happen to the users of the second smtp domain, will they be able to send messages using the old domain address?
Also I need to add the users on the machine that I want to retire to the new machine, what would be their email address @liveserver.com or @retireserver.com?

Yes.
do you want both servers to accept email for the new domain?

there will be no two servers !!!!, only one server will be alive @ the end, the @liveserver.com

users of @aliveserver should continue sending emails as usual, and @retiresrver.com users should send their messages via @aliveserver.com server but all their messaes sender addresses should apear @retireserver.com
does that make sence?

I will start the changes, Thanks

I want to create a user called test this user should be recieving mail from both @alaiveserver.com and @retireserver.com what shall i do, i went to AD to create @retireserver.com and it tells me that the user already exist!
how can i do same user for mulible smtp domains?

you cannot create a user twice. the smtp address has to be unique.

what is the solution, for users who want to use both domains, is thier a way to swich between domains using outlook or OWA?

a user can have two email addresses.
@retireserver.com
@liveserver.com

the only condition is that the email addresses must be unique in the domain

everything is almost working now, except for one final question
say that i want to run my own email hosting company and clients want to host thier emails on my server but using a specific smtp domain @client_name.com and say that i want to host more than 10 companies and the username sam is duplicated in 2 or more companies, what would be the best solution to create the same user name for both companies?
i tried OU and it did not work!

the user's display name can be the same
but the alias and email address must be unique