Exchange 2010 SP1 Multi-Tenant (Step 3 of 3)
Here is the issue. If you use DNS to route your mail then you will have a problem with sending emails between organizations. In order to make this work you must create a send connector that routes the traffic to and from the organizations. Another way to solve this problem is to use a smart host:
New-SendConnector -Name "Internet" -Usage "Custom" -AddressSpaces "SMTP:*;1" -IsScopedConnector $false -SmartHosts x.x.x.x,x.x.x.x -DNSRoutingEnabled $false -SmartHostAuthMechanism "None" -UseExternalDNSServersEnabled $false -SourceTransportServers "Exchange Server"
Now we must tick the Anonymous box on the default receive connector so internet users can send to the Exchange Server:
Set-ReceiveConnector -PermissionGroups 'AnonymousUsers, ExchangeUsers, ExchangeServers, ExchangeLegacyServers' -Identity 'LABDCEX\Default LABDCEX'
Setting External FQDN
Our next step will be to make sure we put the external FQDN on all of the virtual directories.
Set-OwaVirtualDirectory -Identity "owa (default web site)" -ExternalUrl https://mail.exchange.lab/owa
Set-EcpVirtualDirectory -Identity "ecp (default web site)" -ExternalUrl https://mail.exchange.lab/ecp
Set-ActiveSyncVirtualDirectory -identity "microsoft-server-activesync (default web site)" -ExternalUrl https://mail.exchange.lab/Microsoft-Server-Activesync
Set-OabVirtualDirectory -identity "oab (default web site)" -ExternalUrl https://mail.exchange.lab/oab
Now autodiscover is a little different with a multi-tenant deployment. The issue is you will have multiple domain names. Now we all know that autodiscover uses SSL certificates and we don’t want to buy a SSL certificate for every domain name we host.
Luckily there are two alternatives. One is you can use SRV records, and the other is autodiscover redirect. SRV records do have a problem though. Some devices may not check SRV records when trying to discover the email settings. I wasn’t able to get this to work on my iPhone, and Outlook 2007 requires a patch in order to make this work.
Your best bet is just to go with autodiscover redirect.