Outlook is delaying sent emails

I have a user who sends emails, only for them to be delivered 12+ hours later.  There are multiple users on her workstation, so we have already verified that the problem is only with her profile, rather than the computer itself.  We have also checked the Exchange server, and of course it doesn't see any emails from the user until the 12+ hour time frame after she hits "send".  I've already checked to make sure any settings in her Outlook account would be causing this, but everything seems to be at default. Any help would be greatly appreciated!