We are having problems with sending emails to specific users. We have created contacts and some of these contacts we cannot send emails to. We get the following error.

"Exception while trying to send notification for the request."

I can send them an email just fine from outlook. We have created connection exceptions for the server and recipient in exchange and it is not making a difference. We are not getting a bounce back in exchange, only in Support Center. For most users we can send just fine. But for some contacts, we cannot send to them at all. I have verified that this happens when replying but also when clicking on their email address from contacts.

I have tried recreating the contacts several times but does not make a difference.

Is there any other logging besides the systems log in the UI? I cannot troubleshoot the issue with no logging.