I'm currently in the process of upgrading from Exchange 2007 to 2013, and have been moving mailboxes from the old server to the new one. I have a few mailboxes that are over 20 gigs in size. I've set up limits with the new server to restrict the size to 10 gigs max.
It seems that running archive on some of these mailboxes didn't help much, most likely because the bulk of the e-mail is on the server, but not in Outlook, since it's over a year old. That being said, I figure I have two choice - 1. Delete e-mail older than 1 year on the server to reduce the mailbox size or 2. Create a new mailbox in Exchange 2013, export the data in Outlook to a PST file, disconnect (delete?) the old mailbox, create a new one on 2013 and import the PST file.
My concern with #1 is that hard drive on the old server is very slow right now, so deleting all that data would take a very long time. I'd like to do #2, but I want to know for sure what issues I would face. I assume internally, the current autocomplete address for this user would not work, but other than that, I don't know how much of an issue this will cause.
Looking for advice on how to proceed. Thanks.