Exchange 2003 multiple domains with ability to choose sending address

I need to host a 2nd domain on my Exchange server.  Most articles I find discuss how to simply add another domain to the recipient policy area.  However, if I understand this properly, only one domain can be the default for a user and all "reply to" information will reflect this domain.  My users need to use both domains though. When they send a reply, it should reflect the domain that the mail was sent to.  We currently do this using separate POP3 e-mail accounts.  Outlook automatically send the reply through the account it came in on and for new messages we can select which account to use in the client.  I want the same scenario under Exchange 2003.  So a given user might have: and

I've read that the only way to do this is to set up separate boxes.  Does this mean I'll have to setup another domain in AD and if so, how?  My current setup is that I have one AD domain that serves one e-mail domain,  
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ikm7176Sr. IT ManagerCommented:
When you have more than one address type, you must specify one address as primary. The primary address is the one that appears in the From line in outgoing e-mails.

visit , they have the software which suits your requirements.
pcspcsAuthor Commented:
I don't want to use third party software for this solution.  I'm perfectly happy using the solution that requires me to setup two separate mailboxes for each user, just like they currently have using POP3 accounts.  The question is how to setup AD and Exchange to allow and to exist on my same server, each one as a separate account.
Thats easy enough to achieve.
Don't have either account with the user name of joe. Make them joe.smith and joe.jones as the username. Configure joe.jones@ and joe.smith@ as their email addresses.
Then disable the option for RUS to update automatically and enter your prefered email address on each user. Make the new address default and Exchange will accept them.

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pcspcsAuthor Commented:
I think you misunderstand.  Joe is one person.  He works for both companies.  When he's working with customers of he needs to appear (both in new messages and replies) as  When he's working with customers of he needs to appear as  Changing his email address would be out of the question anyhow since he already has customers that know him by each of his two addresses, and  It currently works just fine with being accessed one POP3 account and being accessed via a separate POP3 account.  Outlook automatically replies using the account the original message was sent to and an account can be chosen from the accounts menu when sending new messages.

We want to move mail hosting for both (which happens to also be the internal AD domain that he can locally log into) and has already been moved to the internal Exchange system.  I need to know how to host mail for on the same server.

Perhaps a better way to have asked this question would be to ignore that some users are on both domains and just ask how to host mail for two unassociated companies with unassociated domains on the same server.  If a user happens to work for both companies, they'll have an account on each system.
David WilhoitSenior Consultant, ExchangeCommented:
The scenario I have outlined above is the resolution for your problem.

You cannot have two accounts both called "joe" on the same system. Therefore you need to identify them uniquely. If one account is called "joe" and you add the second domain to Exchange then Exchange will add the second domain. The problem is that you have no means with Exchange natively to choose which address the email comes from. The utility mentioned above is the fix for that.

Alternatively, what you can do is have the email messages all go in to the same account using the forward option in Exchange and then use the from line to control which account they come from.

pcspcsAuthor Commented:
Yea, the scenario would work as long as Joe Jones doesn't mind being known as Joe Smith to some of his customers. :-)

Seriously it doesn't make sense that I cannot have two accounts called "joe" if they are on different domains?  If they are for different domains, then Exchange should be able to distinguish them apart.  That would mean that if I'm a hosting provider I can't host email for two customers on the same server unless I make sure their user names are unique, which would be impossible.  That's essentially what I'm trying to do here -- host two company's mail on one server.  I'm sure plenty of providers do this, but I've never seen a requirement that my users can't have anything to the left of the @ that overlaps with what some other company who might be hosted on the same server already took.  The way this is solved on Netmail is that the username is actually the whole email address.  Surely there's a way to accomplish this with Exchange, a much more sophisticated system.

You say that Exchange doesn't know which address mail is to come from.  Would it not work the same way with two exchange accounts as it does with two POP accounts?   I would assume that if I added both of Joe's accounts to Outlook just like I currently have two POP3 accounts added, that Outlook would have the same drop down menu for choosing an account as it does now for POP3, except that instead of each account being one of his POP accounts each one would be one of his Exchange accounts.  I've not see this done, but that's what I'm after.
David WilhoitSenior Consultant, ExchangeCommented:
I think domains is confusing here...SMTP domains, have as many as you want, but only one is primary address on the mailbox/user. AD domains, different. Still though, you cannot have 2 identical objects in the forest. And yes, you can use the UPN which resembles the email address, but there's still only one of those for a user object. This is a unique object in AD, not a listing in a POP site. You can only have one mailbox per user object. So unless you want an exchange server for each SMTP domain, which is a different forest (and no, that isn't what you want), then you either allow messages to go out with the primary address, or use a 3rd party tool that allows the Outlook client to choose which email address they send with. Just a short analysis....

pcspcsAuthor Commented:
"And yes, you can use the UPN which resembles the email address, but there's still only one of those for a user object."

But I'm not trying to make this work for a single user object.  I have no problem creating two user objects - one to handle mail for each account.  One user object would be created for and another user object for  Joe would then add both of these accounts under Outlook.

Is that not possible?

If this requires creation of another forest, AD domain, or OU to hold the various user objects, that's fine with me.
The solution I have given you above is the way to do it. As long as the username and the email addresses on the accounts are unique then the AD will let you enter them.

You need to make sure that neither of the accounts are called "joe" as this could cause problems with email addresses and other objects. Creating two accounts with joe1 and joe2 as the Windows usernames will be fine. Then attach which ever email address you want to the accounts.
Both accounts will require an email address on your primary domain - but this does not have to be the default address that emails go out with - once the accounts are created then you can adjust them each by hand to change the default addresses.

It is a very common question with multiple internet domains on one server.


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pcspcsAuthor Commented:

Unless I missed something, the solution you provided will not work for me because it's an absolute must that Joe retain his two existing email addresses of and  I cannot ask all users to give up one of their existing e-mail addresses.  They also expect that when they reply in Outlook, the reply will originate from the account the original message was sent to since that's what it does now.  

Further, we'll later add a few domains that are hosted for other unrelated companies.  While these users will only have a single address, I won't be able to require that they don't pick any names that overlap with any names at other hosted companies that they know nothing about.  Chances are they wouldn't overlap, but you never know.  These folks will probably only access via POP3 though... not sure yet.

Kidego, you mentioned that I can "UPN which resembles the email address, but there's still only one of those for a user object".  Does this mean that I could use the full email address as the user object name, thus making them unique?  If so, how?
David WilhoitSenior Consultant, ExchangeCommented:
This is what I was referring to:

ikm7176Sr. IT ManagerCommented:
I will take what I wrote and break it down further.

"Don't have either account with the user name of joe. Make them joe.smith and joe.jones as the username.
Configure joe.jones@ and joe.smith@ as their email addresses. "
ADDITIONAL NOTE: This is an interim step. I could possibly have used a better example of joe1@ and joe2@.
The KEY point is that if you create an account with "joe" as the username then RUS will apply joe@ to all domains on the first account. Undoing that mess can provide interesting as you need to allow time for replication of that information (adding the email addresses initially, then removing them, then adding the new ones).  

Then I said...

"Then disable the option for RUS to update automatically and enter your prefered email address on each user. "
ADDITIONAL NOTE: By this step I meant that you could enter on the first account and on the second account.

Then I said:
"Make the new address default and Exchange will accept them."
ADDITIONAL NOTE: The end result is two seperate accounts, both with joe@ on their email addresses.

As the others have already said, you cannot have two objects with the same name - beit email address or username. However with care you can change the default email addresses so that the username and email address are not the same. The only catch is that you cannot do it through the wizard, you need to make manual changes directly in ADUC.

The last hosting company I worked with created all their users with username@companyname (not the domain name and it was something short).
This meant that you could have jsmith@cars, jsmith@trucks etc.
If you are likely to have lots of unrelated companies on this same server perhaps that is the way to go - it would make identification of who the user belongs to much easier.

Somehow an easy task has become over complicated and it is difficult to see where.

pcspcsAuthor Commented:

Thanks for the additional info.  You're right, it was much easier than I was making it.  

I created two accounts, joe1 and joe1.  I set an smtp address for joe1 of and one for joe2 of

Unfortunately, I found out that Outlook won't let you add two Exchange accounts like it will two POP accounts.  I can get around this by having the user access only their primary one as an Exchange account and access the 2nd one as POP3.  They can still file their POP3 mail in the mailboxes that get stored on the Exchange server so they are available when they login via OWA.  With this method, they can use the "account" drop down to choose which one to send from and replies will always go out from the one they arrived from.  

The only down-side of this is that when the user is working remotely via OWA, they won't get any new POP3 mail when logged into that first account where all their mail is stored.  They also won't be able to send mail from the 2nd account unless they logout of OWA and back in with the 2nd account, but they won't be able to file their messages in their folders that they normally use (since they'd be tied to the first account).  It'll be sort of a kludge when working remotely, but it will work somewhat.

Thanks to Sembee and Kidego.  I'll split the points.  If you have further comments on the "downside" I wrote about above, please chime in.

pcspcsAuthor Commented:
By the way, I did try the software mentioned.  It was okay, but sort of cumbersome to use.  If used, it would be almost a requirement to also get the com plugin that will automatically select the account for a reply that the original came into.  Perhpas the biggest downside is that it doesn't help when using OWA.
The waty I deal with this is to setup the users's exchange account with both addresses like you currently have. Then in Outlook, add a pop/smtp account for the second address, with the smtp server set to the exchange server. Then in Send/Receive groups (it is a few clicks deep) you set the pop/smtp account to be for sending only, not receiving. So what username/password you put doesnt matter.

Then when you create a message, you can choose the account to use.
pcspcsAuthor Commented:

That makes sense. There is one advantage to letting Outlook pull the mail in via POP though.  By doing so, Outlook knows which account send replies out on automatically, so the user doesn't have to remember to switch.

But the biggest problem with all of this is the lack of any solution for OWA users.  It seems like it would be a simple matter for MS to add some way to choose an "identity" natively that would function in both Outlook and OWA.  Maybe will see it in some future version.

I think the following link my be your answer:;en-us;327000#3 

I too am looking for a solution to this problem & have the same setup as stated in your original question.  While IvaSoft's software is a solution, my boss would laugh in my face if I told him that our new efficient email solution requires him to click an additional 10 times than he currently does to send a new mail from one of his may companies email addresses!!!

Now for OWA.....
By the way, it is possible to open multiple exchange mailboxes in one outlook 2003 session.  It's just not the way you would think to do it.

Tools->Email Accounts->View or change existing->select the exchange account->Change->
More Settings->Advanced->Open these additional mailboxes->Add......

When you do this, it works similarly to the POP solution, in that replies go out as the person that got the email.  

Also, if you want to solve selecting the from user on a new email, use a custom form for the person's inbox.  Then when you do a new email, it automagically selects the right account.  

I did this for hosting my personal domain and my business email account.  That way I don't have to use POP and I get full exchange functionality of both email accounts in outlook.

OWA is still an issue.  I6/A=ht look into that.  

Hi Guys....

Take a look here...
Fixes the OWA issue as well :)


Taras Bredel
Humm, that must have been an issue with an earlier version / service pack.  I have Exchange 2003 SP1 on a 2003 server and there's no problem with users from both smtp domains accessing OWA with /exchange.  That works fine for me, I didn't make the change referenced in that article.  What I was thinking about looking at (and haven't yet), was modifying the code in OWA to actually open multiple mailboxes at the same time, so you get an integrated view of both.

pcspcsAuthor Commented:
So it still looks like there's no really good solutions that are transparent for users and works in OWA.  It seems that MS is going to have to include a "send as" capability to OWA in the future similar to choosing an account when using multiple accounts in Outlook.  I remember seeing an email client (Pegasus Mail, I think) that I think used the term "identities".  The neat thing was that if you told it what identity you were using before starting a new message it would insert the appropriate signature file too.  What's seems so strange about this to me is that this seems like it would be an extremely common scenario these days and I would think that this many versions down the line this would have already been addressed by MS.  Oh well, guess we'll wait and see!
I know you have accepted a solution above, but I thought I'd share mine simple solution.

Joe has 2 e-mail address which he needs to send FROM:

Create 2 mailboxes
First 1 being Joe's main mailbox (with Joe@abc for his SMTP)
Second 1 being a dummy mailbox (with Joe@xyz for his SMTP) [this mailbox is never used]

Give Joe's main mailbox full access to the dummy mailbox
Have the dummy mailbox forward e-mails to Joe's main mailbox

While in Joe's main mailbox, browse the GAL for the dummy JOE & save his details as a CONTACT
Hide the dummy mailbox so you don't cause any confusion for others.

When Joe sends an e-mail from his main mailbox the SMTP address will be Joe@abc
When Joe wants to send as Joe@xyz he enters Joe@xyz from his CONTACTS into his FROM field.

Tried & Tested
chammittCommented: one mentioned anything about Virtual SMTP Servers...if you only use one Internet Virtual Server and no smarthost or gateway product...then you are going to run into problem with the email headers reporting the masqurading domain name for all domain email addresses you have...

Meaning, that if you are looking for a true need multiple Virtual Servers...otherwise...

....all of these addresses may look as though they are coming from let's say or from each indiviual smtp domain...

chammit is totally right. We ran into the same problem in our company. We want to host two domains and have complete anonymity between the two. The problem is not when you receive mail (you can receive mail for thousands of different domains), the problem is sending mail out as when your default email domain address is

We are still trying to draft a solution for this. It cannot be done with SMTP Connectors (in Routing Groups) because, according to Microsoft, only one Virtual SMTP Server can bind to the store to send email out to the Internet.

What we are thinking of doing is having a smarthost(relay), Windows 2003 Web edition SMTP server relay mail for us out to the Internet for both domains. This smarthost will stamp emails going out and coming in the message headers, sooo....we give this smarthost a dummy fqdn like

I don't know how else to do it. Using the Exchange hosting solution or a seperate Exchange vertical will be too much money. We have to come up with a solution to host 2 domains using one Exchange vertical infrastructure.

BTW, Microsoft Premier support does not have a solution for this. You are on your own. Apparently, Exchange 2000/2003 (supposedly an enterprise messaging system) cannot send out emails to seperate smarthost for different domains.

Other solutions will be entertained. Thanks.....

hi pcspcs,

I don't care about the points, but here is how I solved the problem you were asking about. I got the information from somewhere else on the internet.

First, create the UPNs for all your domain names. This is more or less for a convenience, because wherever they need to login they can use the instead of
Open AD DOMAINS AND TRUSTS (not users and computers). Right click on Active Directory Domains and Trusts (the top item, not the name of your organization). Select Properties and there is where you add the domain names via as UPNs. Add all your domain names there. Here the link with better instructions and pictures:

Create an Organization Unit for each domain name you need. It's OK if the 'Users' area in the root of your AD already has lots of users that you don't want to manually move into a OU. My root AD is my company name, so it doesn't make a lot of sense to have an OU with the same company name, so I left them in 'Users'.  Anyways, create OUs for the other domains. Just use the domain names as the OU names.

Once you're done creating the OUs in the AD Users and Computers tool, open up the Exchange Manager.

In Exchange Manager, open up the Recipients folder and open Recipient Policies. You will see' Default Policy'. View the Properties. It should only have one domain name there, the domain name of your AD root. Right click on Receipient Policies and create a New Policy for 'Email Addresses'. Name the policy ' Email Policy'. Click on the Modify button. Select 'Organizational Units' from the list next to 'Find'. Click 'Find Now'. Click on the domain name OU from the list. Click OK. Click on the Email Addresses (Policy) tab. Add your new SMTP policy there, it should be - the same as the OU you chose. Edit the X400 rule. Type your domain name/OU name in 'ou1'. Click OK, OK.
Repeat for all your domain names. Right click on each Policy and select Apply Now.
Once that is all done go to Recipient Update Service (right about the Recipient Policies folder). Right click each RUS and select Update Now.

Delete the users you created from before if noone has used them yet and no mail is in them (i don't know if they can be cleanly moved or not, you might check on this). You can see if theres any mail in the mailboxes using Exch Sys Manager under Admin Groups/Servers/First Storage/Mailbox Store/Mailboxes (click on Mailboxes then on the View menu select Add/remove columns and turn on the Full Mailbox Directory Name column.

Now go back to your OUs in AD Users and Computers and create your accounts. Click on the OU for New->User. Fill out the info, but for Display Name add '(' to it, example: John Doe ( User logon name (same as the primary email address). In the list next to his logon name, select the proper domain name. For user logon name enter thisguy1. Click OK. Double click on the user you just created. Copy the Display Name. Paste it into Description and add "(" to it - this will be handy later trust me. In the Email box enter that email   Click on Email Addresses tab. Add SMTP emails here, make sure is listed.  You can delete the entries. Add any email aliases ( for that same mailbox here. Check the X400 entry and make sure ou1 has in it. Set the SMTP email as the Primary Address.

Repeat for all users in that OU then go to the next OU.

Now if you followed everything right, the users can login to Outlook Web mail using their real email address ( just like you have it in the AD user account because we added those UPNs. The other bonus is that by adding the ( text to the Full Name and Description fields you will have a lot easier time figuring out who you're trying to work with in various screens in Outlook (like the address book).

If you add everything to the Default Recipient Policy, every time you create a user in AD it will automagically have all those domain names and you have to remove them. The way I showed you is better.

I still have one last problem, which is that Outlook won't let you setup more than one Exchange Mailbox. I need to figure this last part out and i'm going to post a question about it.

If you use the POP3 interface to retrieve the mail, then you're pretty much already done. Did you figure out how to enable POP3 - mine was turned off by default. In Exchange Sys Manager go down in Admin Groups  / Servers / Protocols. Open POP3 click it and Start it.
Using POP3 you enter as the username and his password. Outlook figures out who to send the replies from because of the separate mailboxes (except for the Aliases).

Now I have the 'crazy' idea of wanting to really have all these mailboxes under one user inside Exchange Server so that Outlook Web Access (try going to works correctly. As it stands with the POP3 setup, all your mailboxes are always empty because you're storing the messages on your local machine.
Add one Exchange account into your Outlook (it only lets you have one) and you can easily right click on folders and Copy the contents into the Outlook boxes. In Outlook, On the Email Accounts config screen you then set 'Deliver new email to the following location:' to point to the 'Mailbox - thisguy' exchange mailbox. That makes all emails received (whether POP3 or exchange) get placed into the exchange mailbox on the server.
Unfortunately, if you use OWA to reply to an email guess what happens - it goes out under that mailbox user instead of whatever email address it came in on.
In order to 'check' the mail you would have to log in under each separate login (, in order to 'check your mail' in OWA. Any emails you send by doing this end up in THAT mailbox's Sent Items.
Trying to make it work the way we want it to is just screwy and i'm going to see if anyone else has any solutions.
Someone said creating Recipient Policy based on the OU doesn't work.;en-us;296112

If you enter all the domain names on the Default Recipient policy all you need to do is delete all the extras every time you create a new user.
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