Delivery has failed .... #550 5.1.1 RESOLVER.ADR.ExRecipNotFound

We recently migrated a SBS 2003 to Windows Server 2008 with Exchange 2010 with a new internal domain name:
Old: domain.local
New: domain.internal

We cleared out Outlook Nickname Cache of old addresses and replaced with new so to avoid this issue, but when ever a User replies to an email to an internal staff member Outlook will try and send using Old Domain Name.

Can I adjust User Accounts so both are accepted somehow so I dont have to adjust Outlook Nickname Cache etc.?
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Simon Butler (Sembee)ConsultantCommented:
This blog posting from the SBS team explains everything.

Cleaning out the nicknames is not enough to stop the problem, you need to have the additional entries, or the users need to be told that when replying to old email to select the recipients fresh.


Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
FlippAuthor Commented:
lol ... yeah just found this and other postings on this.

Thanks Simon.
FlippAuthor Commented:
Thanks again for quick reply - much appreciated.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.