eM Client program was open all night and didn't sync

Installed eM Client (v7.1.3) for the first time yesterday and was receiving emails throughout the day just fine.  Left desktop and the eM Client program on and open all night.  This morning woke the pc up and the eM Client was there as I left it with no new email and a last sync date/time of yesterday when I went to bed.  I waited a while before doing anything and no syncing until I finally hit the refresh and emails started coming into the inbox.  Synchronization settings are set to:  sync at startup and sync every five minutes.  Please help!  I really want to like this program.