My resent project involved some non very standard migration requirements that led me to some interesting discoveries which I wanted to share in this post.
In particular, Source mailboxes were extremely large (~ 122 GB was the largest but others were not too far). Target environment, on the other hand, had mailbox quotas enforced down to 1.5 GB. Given the limited timeframe we had, customer decided to simply migrate into the empty mailboxes (however still carry over Calendars, Notes and Contacts) and then give users simultaneous access to the Source and Target mailboxes via single Outlook 2010/2013 profile (not 2 separate profiles!). This, surprisingly, brought up some migration challenges. But first, I wanted to describe how to migrate into the empty mailboxes just skipping Emails while giving users everything else inside mailbox. We were using legacy QMM Ex agents so the approach only applies to those.
I. Skipping all Emails.
QMM has the logic to only migrate certain number of “last days” of Emails, but then you are still faced with some inconsistencies of how this moving window rolls during the prolonged sync giving some users more and some less. On the top of that, having access to the Source mailbox would have produced an overlap. Then Contacts, Notes etc. So I decided to improvise and tried legacy agent message class skipping logic. On Exchange Data tab in QMM, click on Tools | Options | Additional Parameters for agents, edit MessagesToSkipTypes and append:IPM.Note. This basically skips all Email messages during the mail sync, while giving user everything else. Just add mailboxes into the Calendar and Mail sync, configure your switch collection and user will switch into the empty Target mailboxes. Contacts will be there, Notes, Tasks, Journal, Calendar… but no Emails.
II. Getting users to have simultaneous access to the Source (switched) and Target (active) mailbox in a single MAPI profile (newer feature in Outlook 2010/2013, and both were tested by us) – hmm… not so easy.
– First challenge that awaits you, if you have same set of Source and Target proxyAddresses (Source primary is set as secondary or migrated as primary), Autodiscover brings some interesting effect. You cannot see 2 separate mailboxes, it “sort of” blends into one. Account settings reveal 2 mailboxes added, but you only see one. This is because Authodiscover sees same Primary SMTP address being part of 2 mailboxes and then blends them together. Pretty frustrating to deal with that effect, but in our case Target mailbox had the new Primary SMTP and we simply stripped secondary old-Primary from Target and secondary new-Primary from Source. That made us half-way through.
-Second challenge was very unexpected and literally impossible to work-around if you really want to have 2 such QMM-migrated mailboxes in your profile. When syncing mailboxes with the legacy agents, MAPI_SOURCE_KEYs are preserved. Well, Outlook doesn’t like that… 2 different profiles – not a problem, but not when you want them combined into one. It still shows 2 mailboxes but not updating the content of secondary one, only showing unread count. Delete/re-create Target mailbox and the problem goes away.
Another interesting scenario in the migration world of endless “gotchas” which await you around the corner… be well armed and prepared 🙂