Hello, we have the following problem: We(domainA) have an 2003 domain with exchange 2003 server. We also give ict services to a second firm with a separate domain.(domainB) They have no exchange server. They have asked us if it's possible that we give them email from our exchange server. Can we do this? (there is no trust between the two domains) what is the best solution?

To have your Exchange environment handle their email isn't a problem but rather how thay will be able to access their mailboxes. If there's no trust you need to give them login accounts into your environment which isn't always feasible. If you establish a trust you could create mailboxes that are accessed by an account from the other domain like described here: Understanding and using the External Associated Account in Windows Server 2003 and Exchange 2003 Do you publish your Exchange 2003 to the Internet via some reverse proxy today?Jesper Bernle | Microsoft Community Contributor 2011 Awardee

Does DomainB has any messaging application... If not, Then you will have to setup a Trust between domain A and Domain B. Then Create mailbox at Domain A and give associate external account permission to domain B user account so that he can access the mailbox.Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Hasnain Shaikh| My blogs: http://messagingserversupport.com

Create accounts and mailboxes on your domain and have them access their mailboxes via OWA or RPC over HTTPs.

Create accounts and mailboxes on your domain and have them access their mailboxes via OWA or RPC over HTTPs.

To have your Exchange environment handle their email isn't a problem but rather how thay will be able to access their mailboxes. If there's no trust you need to give them login accounts into your environment which isn't always feasible. If you establish a trust you could create mailboxes that are accessed by an account from the other domain like described here: Understanding and using the External Associated Account in Windows Server 2003 and Exchange 2003 Do you publish your Exchange 2003 to the Internet via some reverse proxy today?Jesper Bernle | Microsoft Community Contributor 2011 Awardee

Just as above friends said, you can create mailboxes for that users in your domain or follow Jesper's suggestion to do that. If you go to create user mailboxes, they need use user account in your domain to login the mailboxes. If you follow Jesper's suggestion, they can use their own accounts to login the mailboxes. Thanks, EvanEvan Liu TechNet Community Support

Just as above friends said, you can create mailboxes for that users in your domain or follow Jesper's suggestion to do that. If you go to create user mailboxes, they need use user account in your domain to login the mailboxes. If you follow Jesper's suggestion, they can use their own accounts to login the mailboxes. Thanks, EvanEvan Liu TechNet Community Support