I am currently using 'Microsoft Outlook 2016 MSO (8.20080) 32-bit', on a Windows 10 Pro Dell Precision 5510 Laptop. Will allow someone who knows how Outlook is supposed to work, to tell me what changes to my configuration should resolve this undesired behavior, or confirm it is a bug that should be fixed. Please bear with me, and read the entire story - it is somewhat convoluted and difficult to explain, at least for me, because only the act of opening the outbox causes this issue. Of this new and undesired behavior are described below. I believe this behavior began after the July updates, but I am not certain that it is related to those updates, or to the unintended change from a perpetual Outlook 2016 installation to an Outlook 365 subscription installation. You can close and reopen Outlook after setting it to work offline, if you are in a hurry.I have used Outlook for some time (many years), but in the last week or so, have observed a new behavior which prevents emails in the 'Outbox' from sending when I initiate a send/receive cycle, if I have opened the Outbox, (not any emails therein, just the

A very large message may require longer than 5 minutes to stop processing.

This is one time when patience is a definite virtue - make sure you give Outlook plenty of time to stop processing the message before trying to delete it.

Wait a few minutes, longer if the stuck message is really large, then delete it. If your version of Outlook doesn't include a Work Offline command, or you are having problems getting Outlook into offline mode, disconnect from the Internet or disable the network card in the Control Panel, Network. When Outlook is Offline, the button is highlighted and Working Offline is in the status bar on the lower right.Īfter the stuck message is deleted (or the attachment removed), set Outlook back online. The screenshot shows the default setting of On (as in Working Online). Work Offline is on the Send & Receive ribbon. If you want to keep the message but remove the attachment, open the message and remove the attachment then Send. Use Shift+Delete to delete it permanently, especially if you have an IMAP account as it will create an error trying to sync to the server. Wait about five minutes or more for the mail spooler process to shut down or close Outlook and reopen. If you have a large message stuck in the Outbox and receive an error message when you try to open or delete it, you need to set Outlook to work offline.

Items stuck in outbox office 365