one message shows up on Outlook.com but will not show up in Outlook 2013

I usually run Outlook 2013 to access my hotmail account.  It uses EAS to access my account.  I logged in to Outlook.com later in the day from a web browser and noticed a new, unread message there in between other read messages.  For some reason, that particular message will not download to Outlook 2013.  I even deleted my account in Outlook 2013 and re-added it and had it download all the messages again and for some reason it would not download that particular message.  The message still shows up in my inbox on Outlook.com, but won't download into Outlook 2013.  I'm just concerned I'll miss more messages during the day using Outlook 2013.