I exported some contacts from my exchange management console 2007 to a pst file because I was changing from a company email to another company email. 

The file exported ok and the import in outlook 2010 worked just fine. But when I write an email using this catalog I imported, the emails never goes out of outlook. When I type the emails (ignoring the catalog) it works. I really dont understand what went wrong. I believe is something on the configuration of the exporting mail contacts.

Can somebody help me?

Hi,

Do you means export contacts to .csv file by EMC in Exchange 2007 then import it to Outlook client, or export contact from Outlook?
Besides, I want to double confirm some points, please help collect answers for those questions:
1. How about click the e-mail in contact information and send a message?
2. How about new e-mail then type e-mail and send message?
3. Is there any error message when click Send/Receive All Folders?

Please try to reset Auto-Complete list first: 1. Close Outlook client. 2. Run Outlook.exe /CleanAutoCompleteCache.
Besides, try to re-edit the information of those problematic contact for test.

Thanks

I mean export contacts but is to a .pst file in Exchange 2007 then import it to Outlook client.

Answering the questions:
1. How about click the e-mail in contact information and send a message?

When I do this, the email stays at the outbox box. It's stuck, never sends.
2. How about new e-mail then type e-mail and send message?

When typing (not using the contact information) it works. But I want to use the contact information.
3. Is there any error message when click Send/Receive All Folders?

There is no error message, unfortunatly.

It happens with every user I imported this contact information. No one can send email using it... only typing.

Now I received an error message:

Sending' reported an error (0x8004010F) : 'Operation failed. Object not found.'