The flow of email is crucial during a migration. It doesn’t matter if the email is one that was scanned in by an all-in-one device, an email forwarded by your CEO’s iPhone, routed by your alerting system or one sent to offsite archive storage. What can you do to make this work smoothly during an Exchange 2003 to Exchange 2010 migration?
First step is to create a bi-directional Routing Group Connector using PowerShell on the Exchange 2010 servers. See this Kb article on how to do that – http://technet.microsoft.com/en-us/library/aa997292.aspx
Next, create your SMTP Receive connector for your applications/servers to use to relay email through Exchange. Make sure that the IP Addresses listed in the ‘Network’ tab in the box with the caption of “Receive mail from remote servers that have these IP addresses” do not include your Exchange servers. Only do subnets for ones that do not include your Exchange servers. Make sure that ‘Anonymous’ on the Permissions Groups is checked.
Modify your Default Receive connector to allow only your Exchange 2003/2010 servers as well as the next hop for incoming email. If you are not using Edge Transport servers, then make sure that ‘Anonymous’ on the Permissions Groups is checked.
Do this for each server with the Hub Transport rule. If you want, you can configure one connector and then copy the RemoteIPRanges to the other servers’ connectors. Use this link http://www.expta.com/2011/09/cloning-exchange-remote-ip-ranges.html for that.
One last change is to modify a parameter on the Default Receive connector on your Exchange 2010 side. This is the connector that talks to Exchange 2003. There is a value called MaxAcknowledgementDelay.
What is it? – http://mikecrowley.wordpress.com/2010/07/24/delayed-smtp-acknowledgement/
What can it do? – It can cause issues with your migration where you will see message processing delays of 30 – 60 min.
How is it fixed? – If your users are experiencing major delays sending emails from Exchange 2003 to Exchange 2010, then you need to set this value to ‘0’.
get-receiveconnector -MaxAcknowledgementDelay 0
Things to watch out for:
- Link state update suppression – http://technet.microsoft.com/en-us/library/aa996728.aspx
- Routing master issue – One of the servers in the Interorg Connector (the RGC) could be getting an error about not being able to contact the Routing Group Master – check the Exchange Routing Engine service.
- IPs allowed to route on the Exchange 2010 connectors
- Smart Hosts on the SMTP virtual server – make sure that the SMTP virtual servers for Exchange 2003 are not set to use SmartHosts for email.
- MaxAcknowledgementDelay – set to 0 if experiencing mail delays.
- Corrupted disclaimers in OWA 2003.