I'm running into a problem where my email client keeps using outdated address information, specifically those annoying IMCEAEX records. I've followed all the troubleshooting steps from a helpful article I found, but I still can't shake them off. I also tried using NK2edit to delete those EX records, but they keep reappearing every time I restart Outlook. Does anyone have any advice on what might be causing this and how to resolve it?
3 Answers
I ran into this issue about six months ago during a client migration. Those IMCEAEX entries are really persistent! The NK2edit method works for a bit, but you need to fix the root cause. I found that checking the Exchange side helps. Look for any lingering legacyExchangeDN attributes or uncleaned mail-enabled objects from a previous migration. You might also want to run a Get-Recipient command on the problematic addresses to see if any phantom objects are messing up Outlook's info. Switching to online mode temporarily can tell you if it's a client-side caching issue or something on the server side that's still holding onto old data.
Exchange uses the legacyExchangeDN for resolving recipients internally. If you see those addresses popping up, it usually means a recipient was deleted and recreated. To prevent this, always take the legacyExchangeDN value of any recipient about to be deleted and apply it as an x500 proxy address to the new recipient. If you're facing this issue now, you can convert that IMCEAEX string to the legacyExchangeDN format and apply it as an x500 address for the replacement recipient. It should resolve the problem pretty quickly.
Did you migrate the emails from a different mailbox or have any previous issues with that mailbox? Often, Outlook caches and resolves contacts to their X500 addresses. If something went wrong, like a migration to Exchange Online without proper setup or if the mailbox was deleted and recreated, that might explain it. The new recipients could have different X500 addresses, causing the old cached ones to fail. A good practice is to keep a copy of the X500s to apply them to new recipients. If you’re replying to an email, just delete and re-add the recipient to fix it.
That's actually what happened! We migrated from on-prem Exchange to Online, then merged with the parent firm with SkyKick, so things are a bit messy.
Thanks, I'll try this!