I'm from DaveP's LEA and as a traded section we're happy to do paid work for independents too, so it's worth asking Suffolk(?). We did hundreds of migrations, I got to do the initial viability testing, troubleshooting throughout, special cases, script and code for automation etc., and probably now count as a world-expert. Could write several pages, but key points:
* It's not perfect or trivial, but a migration from Easymail does work.
* The Live@Edu migration feature will only migrate EasyMail mail items/folders. EasyMail contacts can be manually exported to a CSV file and after conversion to the Outlook2003+ contact export format, they can then be manually imported into Live@Edu by users. I don't believe Easymail calendars can be exported, but very few of the schools we worked with had them.
* If any users have been using POP3 to download mail from EasyMail then you have a potential problem. If they used Outlook that mail will be in a PST file on some local machine and you can connect Outlook 2007+ to Live@Edu and import that PST file into their Live@Edu mailbox. In these cases I don't recommend carrying on with POP3 (reconfigured to point to Live@Edu), because having all your mail in the cloud, reachable from anywhere, is a significant part of the raison d'etre. If users have downloaded mail via POP3 with some random mail client then all bets are off.
* All your users will have to start using Live@Edu at the same time, shortly after a necessary DNS MX record change. With suitable preparation you can achieve that "cutover" in an hour or two, but give yourself some leeway and plan for a day when users should not expect to be able to access their mail (therafter they access it from Live@Edu).
* Before committing to this, do carefully review the Message and Recipient Limits, especially the Recipient Rate Limit which will likely be an issue for anyone who has previously been mailing school news etc. out to a large (500+) number of parent mail addresses.
