Hi

I am about to do a migration at a customer from Exchange 2010 to 2013. 

In my lab I can not get rid of the password prompt in Outlook 2007 when the user is on Exchange 2013 and the shared mailbox is on Exchange 2010. 

Anyone have any ideas? Everything works fine if I give the credentials, but that might not be an option for these 5000 users at the customer :-)

This is not the sollution 
https://support.microsoft.com/en-us/kb/2834139

BR
Steen

Checkout this earlier discussed thread with almost similar concern and having suggested solution by expert.
Exchange 2010 to 2013 Migration, Outlook Anywhere Password Prompt:
http://community.spiceworks.com/topic/696751-exchange-2010-to-2013-migration-outlook-anywhere-password-prompt

Also, have a look on this informative post:
http://www.geekmungus.co.uk/microsoft-exchange/exchange2010toexchange2013migration-outlookanywhereclientsusernamepasswordpromptappears

Off the topic, while need to migrate users mailboxes  from Exchange 2010 to 2013 you may also try this automated solution i.e. http://www.exchangemailboxmigration.com/ in order to achieve the migration task more easier.

• Edited by maccarter 21 hours 34 minutes ago
• Marked as answer by steenpedersen 21 hours 9 minutes ago

Argh

You let me in the right direction :-)

I forgot to set NTLM on Outlook Anywhere on the Exchange 2010 environment, in my lab.

Now everything works without prompt.

Thanks.

BR
Steen