Two Exchange Servers in the Same Forest But Different Sites

How many domains do you have? If only one domain then the MX record in DNS will tell which server to deliver to. The easiest and most practical solution. If you have several domains you can split between the two sites.

There will be one Windows domain and one email domain.Each needs to view calendar information and emails across the both offices.

What would you suggest?

If you set up a VPN connection between the two sites then you can do that by default as the Exchange servers will belong to the same organization. I would suggent only one Exchange server though to keep things simple.

What I would recommend is setting up two MX records, one for each site. This will provide redundancy in case one server is down. How you weight each record depends on your expected traffic pattern. If you have one site that is larger than the other or one site you expect to have a higher volume of e-mail, you should weight the MX to that office as the primary. If you expect the mail volume in both office to be about the same, you can weight both MX records the same.

JJ

Peakpeak

I need to minimise traffic between the VPN. I want to have 50 users in the US and 50 Users in the UK accessing their own Exchange Server. Both servers will be the same exchange organisation.

I guess if you only have one email domain then it can only be delivered to one location.

If emails for the whole organisations is delivered to one site, how does the exchange server on the uk site forward emails to the other exchange serve which is in the us site?

Jim both sites will be using the same email domain.

Right, both MX records will be for the same domain.

Exchange will automatically take care of the routing between servers.

JJ

If the UK site is down. The US site will handle all the email as a failover. What happens to the emails if it cannot be delivered to a UK mailbox?

If the UK ssite is down, the US server will retry delivery according the the rules on your server's virtual SMTP server. The default is a retry for 2 hours but you can increase this value if you want. Once the UK server is back online, the US server will deliver the e-mail to it.

How does the exchange server in the US know to forward emails to the exchange server in the uk for uk users? Is there a setting somewhere within exchange?

Would I need the exchange enterprise to do this?

I presume the exchange server will determine automatically which emails are for the UK based on the routing groups? Do you specify which users are in the UK?

Didn't know your sites were so far apart. Having two different MX for the same domain pointing at two different server is not to reccomend and the emails easily will end up on the "wrong" server. When you say one domain do you mean a windows domain or a DNS domain? If you have different DNS domains for US and UK then the MX pointer will care for it without any special setup.

I have to disagree peakpeak. First, how does the physical separation between sites matter? 20 miles or 20,000 miles, it makes no difference. Having multiple MX records for a single domain IS recommended for fault tolerance and having those MX records point to two different sites is even better as it provides fault tolerance in the event an entire site goes down. E-mail will not end up on the "wrong" server as Exchange will automatically route the e-mail to the correct server.

He already stated that both sites use the same AD and the same e-mail domain...

JJ