Exchange Server Fresh Start

We have a 2010 Exchange Server that has serious corruption in the the information databases. The actual mailboxes are also way too large (some are 30+ gig). We have spent a great deal of time trying to fix the various problems and not had much success, so we have decided to start over with fresh empty mailboxes on another server. We don't want to lose our old mail,calendars, contacts etc so we plan to archive it or export it and then access the old mail from pst files. Some suggestions on handling the other data (like calendars) would be helpful.

We plan to create new mailboxes on the new server using the same email addresses and we would like to bring this online immediately because the current server is so slow it is almost unusable. Then we will start pulling data off the old server and making it available to the various users.

We are looking for some input as to possible pitfalls and maybe other ways to do this.

Thanks.