Possible Cause: A Categorizer forward loop was detected.
The targetAddress attribute is set on a mailbox-enabled user. Hosting Pack: This is a common hosting configuration problem that is caused by an organizational unit (OU) conflict. The problem occurs when someone creates a contact in OU1 and then uses the provisioning tool to create a user in OU2 that has the same email address.
Troubleshooting:
This problem occurs when contactA has an alternative recipient that points to contactB, and contactB has an alternative recipient that points back to contactA. Check the alternative recipient for every contact.
Remove the targetAddress attribute from mailbox-enabled users.
For hosting in which you want to send mail from one user in one company (OU) to another company (OU), it is best to specify the following related objects:
User: SMTP proxy: user@company.com
Contact: targetAddress: user@company.com; SMTP proxy: contact@company2.com