We are migrating from a hosted Exchange 2007 environment to an internally hosted Exchange 2010 server. One problem that we've encountered during the migration is that users complain that when they reply to emails that were imported from before their migration, it bounces because there is organization info attached to the Reply-To address. I can't think of a way to alleviate this issue from the server side of things, but is there some sort of tool out there that can scrub PST files for Exchange organization info and replace those reply-to addresses with just the email address? Surely someone has had this issue before?
What you're getting into is x400/x500 code issues. Exchange routes mail internally based on those codes, not based on SMTP address. So there isn't a way to do a PST scrub.
What you can (and should) do is contact your old Exchange host and get a copy of the x500 codes, then import them into your Exchange 2010 environment. Your bounce messages will stop instantly.