We are using Microsoft's Identity Integration Feature Pack to sync contacts between two separate domains at two separate branches of our company. Recently we have run into an issue with a few of the contacts being pulled/synced from this remote location. When people in our organizaion are sending emails to certain contacts that are being synced from the remote location, the message delivery fails. After looking into the issue we are seeing that this failure is the result of the email being sent to some obscure email address rather than the correct email address. For example, the email address is getting changed to IMCEAEX_O=NT5_ou=44C5AE1BBEE0ED499F607407769311BB_cn=2F31FA0CA187314FA8D6A99BEFC52C36@domain.com rather than [email protected] Clearing the recently used contact list seems to solve the issue, but it does not solve the underlying problem. Because this issue is starting to happen to several different people I would like to solve the underlying cause. Does anyone have any input on how to start troubleshooting this issue? Also, we are using Exchange 2010. Thank you for taking the time to look at this.