We transferred a Client's email from a POP3 service to Exchange 2010 and at least one user has ended up with the following auto reply message when sending to distribution groups.
The distribution groups are stored locally on his PC. It was used before the migration.
Delivery has failed to these recipients or groups:
Firstname Lastname (firstname.lastname@example.org)
The e-mail address you entered couldn't be found. Please check the recipient's e-mail address and try to resend the message. If the problem continues, please contact your helpdesk.
Attached is the process that we used to move the mailboxes. 2Converting-email-to-the-exchang.docx