I need to migrate from Exchange 2003 to Exchange 2013 and would prefer to avoid two stages (Exchange 2003 -> Exchange 2010 -> Exchange 2013). I read somewhere that direct cross forest migration from 2003 to 2013 is supported, but I also read somewhere else it is not. Could you give me proper answer please? Thank you

Hi If you want to use the built-in Exchange tools to do the migration then you will need to install 2010/2007 first - it doesn't matter if you are going cross-forest or not. You can get 3rd party tools which can migrate from 2003 to 2013 or you could export the mail to PST and import it into the other forest. I think it's actually easier and cheaper to install Exchange 2010 and migrate to that first but your organisation may have different requirements. Cheers, Steve

Thank you Steve