Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

When I delete and Exchange 2010 user and recreate them using the same email addresses as their old mailbox, other users that try to email them using the type-ahead look-up suggestion thing in Outlook receive a bounce message.

How can I prevent this from happening?

share|improve this question
up vote 2 down vote accepted

Outlook has always used the LegacyExchangeDN/X500 attribute to send email to internal users, as far as I'm aware. Even though the new user account has the same name and email address the LegacyExchangeDN is different. Your users will need to delete the entry from their autocomplete cache and recreate it.

Note that this will affect replies to emails sent from the original account as well. Any user replying to an email sent from the original account will get a bounce.

The remedy is to add the original LegacyExchangeDN attribute value as an X500 address on the new account.

share|improve this answer
that did it. thanks! – longneck Aug 20 '12 at 19:39
Glad to help... – joeqwerty Aug 20 '12 at 19:41
I tried to add X500 address to a re-created user but it still doesn't work... may i need to wait or address are instantly associated to mailbox? – Tobia Jan 16 '13 at 8:32

Clear the type-ahead cache, and/or have the users delete that particular entry (select the entry and hit the delete button).

Unfortunately, those are stored on the client, and I haven't found a good way to automatically remove a specific entry or entries, short of blowing them all away (and that really pisses people off).

EDIT: Here's a tutorial and tool that claims to do the job, but I can't vouch for it. Wish I'd known about it during my last migration. Do share if it works.

share|improve this answer
I think there's an option to turn this off, and have users the enter the name and click CTRL+K to auto-complete. It's might be an option. – Vick Vega Aug 20 '12 at 18:43
Yeah, you can do that, but they'll still get the bad auto-complete entry with Ctrl-K and be all confused, unless you delete it one way or another. And like I said, users tend to get really pissy if you turn the feature off completely or wipe out their auto-complete. (Been through that hell more times than I care to count.) Ugh. – HopelessN00b Aug 20 '12 at 18:51
that tutorial/utility doesn't work on exchange 2010 and outlook 2010 because the type-ahead cache isn't in a file anymore, it's in a contacts folder. – longneck Aug 20 '12 at 19:12
@longneck Ah, well there you have it. That in mind, you might want to specify Outlook 2010 in your question. Maybe someone's figured it out for Outlook 2010. – HopelessN00b Aug 20 '12 at 19:14

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.