I have a problem where e-mail from one Exchange server is staying in the PreSubmissionQueue for a few minutes and then it is delivered fine. My users are seeing there e-mail staying in the outbox for about the same amount of time. I enable advanced logging on the server and nothing is standing out. I have also checked out DNS and everything seems fine there. I am going to reboot the domain controller and the Exchange server to see if that resolves the issue, but I was wondering if anyone has seen this issue before.