Outlook 2016 stoped updating cause
In Outlook 2003 and older, go to Tools, E-mail accounts, View or Change existing accounts. Outlook saves your Send and Receive customizations in a file with the extension *. If this file is corrupt, the Send & Receive Settings dialog won't open and you may receive send & receive errors.
Find and delete or rename the SRS file for your profile.
If you are using i Cloud and messages get stuck, see Outlook and i Cloud 2: What you need to know for the latest information.
If you are using a Comcast account and messages aren't sending, you need to change your outgoing server to use port 587 or 465 and set Use this following type of encrypted connection to None then click OK.
Instructions for Outlook 2011 for Mac are at Delete Messages Stuck in Outlook 2011 Outbox.In Windows 7, 8 and Vista the SRS file is at Reboot and disable the problem program before starting Outlook.If it continues to cause problems (such as sending works for awhile after restarting Outlook, then stops), uninstall the software.I n Outlook 2007 and Outlook 2003, go to Tools, Options, Other, Advanced and add a check to the box beside Enable Logging (troubleshooting).Because logging can cause Outlook to be unstable, initiate a send and receive and once you've reproduced the error, disable logging. Type %temp% in the address bar of Windows Explorer and press Enter to open the Temp folder.