I have Exchange 2007 setup in two separate forests without a trust relationship. Site 1 receives all incoming mail a forward the mail to site 2. Site 1 has and A record and a MX record for site 2 mail server name mail2.site2.local. Site 2 has decided to separate hub transport and client access roles by adding a second server call mail2.site2.local. Questions: Does site 1 have to add an A record for site 2 or will a MX record forward to mail2.site2.local without an A record.

Hi, An a record is required in your case. As the A record will point to the ip of HUB server which accepts the mail...... Thanks.

Just to understand. The MX forwards mail to mail2.site1.local and on site1 the A record tells the MX record were the server is located. Correct

Hi, Ok -- Your mail server asks the DNS server what is the MX record of the domain to which you have to deliever the mail.... Now when it get the MX record entry it then tries to look for the ip of the server responsible for accepting the mails... As computers understand IP rather then names. Now when the mail server gets the ip address it makes smtp connection to the recieving mail server and asks whether he is the owner of the domain and has the mailbox for this uesr. If yes then it hand over the message to that server else you will receive the bounce back..... Thanks...

Thanks

Well, Dec0der has answered the question solidly Its important to notice if Hub server role were still on the original server, if yes, then we dont need to change the A/MX record since they have already pointed to the Hub server. However, if we separate Hub server role to that second server, the new A/MX record would be required. The key is to point the record to the Hub server on the site 2 (Forest 2)

Hi.. Just a small doubt here, we should have hub transport role in every site. Would it be possible if we have only one hub server role installed in one forest and we do not have hub role installed in another forest. I think this is not possible in Exchange 2007 enviornment. Please correct me if I am wrong. Thanks.Regards,Sunil Bansal

Sunil, if a mailbox server does not have a hub transport server in the same AD site mail will not enter of leave mailboxes of users on that server. Mike Crowley A+, Network+, Security+, MCT, MCSE, MCTS, MCITP: Enterprise Administrator / Messaging Administrator

Sunil, You do not need to create any seperate records for your new HUB server as one DNS host record will create automatically when you install server in domain which help to find IP of new HUB servers. Regarding HUB server in single forest You must have at least one HUB server in EACH site as recommended by MS.Anil

hi,look at here ;http://www.msexchange.org/tutorials/Exchange-Server-2007-Email-Routing-Part1.htmlhttp://www.msexchange.org/tutorials/Exchange-Server-2007-Email-Routing-Part2.htmlregards,Mumin CICEK | Exchange - MVP | www.cozumpark.com | www.mumincicek.com

Agree with Mike

Any update on this case?