Outlook for Mac 15.3 (Outlook 365) gets hung up on Sync Pending

I noticed there was a problem with the date on the mac. Keeps changing to the previous or next day. Randomly changing. I believe the system time interferes with the sync. I fixed the time and the sync hanging stopped after restarting the application.

Hope this helps.

-Kirk II

Thanks to Kirk II I also noticed the clock was set back a day.

Opened the clock settings and selected the “Set date and time automatically” option at which point the date immediately updated with the correct time and date.

Closed and reopened Outlook 2011 and saw the sync was still pending.  Once I selected to Send/Receive the attachments were immediately downloaded and now appear to be working normally.

Locate your account setup file here: ~/Library/Group Containers/xxxx.Office/Outlook/Outlook 15 Profiles/Main Profile/Data/Exchange Accounts/xx/

(the file will not have any extension)

I am an experienced windows user that has switched to macs. All 3 of my macs have this problem, but i noticed that if i change the server, it works really well until auto discover changes the server reference - even though I am sometimes prompted to accept the change I decline, but the server is still modified.

My question was how do I locate my account set up file? For ex-windows users, who may not be familiar with macs, this is what you do:

1. Open outlook
2. Change the server
3. Quit outlook (as the auto discover can work at any time and you may lock the file in the wrong state)
4. Click on Spotlight Search the hour glass in the top right hand corner
5. Type in ~/Library/Group Containers/
6. Go through the directories until you come to the last folder indicated above.
7. The file will not have an extension but will end in "ExchangeAccount"
8. Right click on the file
9. Select "get Info"
10. check the "Locked" box
11. Open outlook

If you are prompted for a password, even though you know it is there and correct, maybe insert the server without the "https://" proceeding it, then repeat the steps above.

I did look at the file (copied it to my desktop and changed its extension to "txt" and notices that it has a call to auto discover - i suppose that this "fix" does not allow it to happen.

Actually seems to be working and as changing the server always worked (but was tedious) i have high hopes for this fix. This sometimes used to happen with my iPhone and iPad when auto discover would change the server name. For this fix I will reserve judgement as I have been struggling with this for months with both 365 and 2011.

PS, Up to 2 days & this seems to be working - it has not done that before...

This seems to have worked for me during the last week but the exchange admin is not happy  There again i have to work!

Come on Microsoft get your act together.

Eventually, after playing around a bit, I realised that the problem goes away if logging is enabled in Outlook 365.

From the Ribbon, Goto Tools -> Sync Errors.

On the window that opens, click on the settings gear at the top right

Select "Turn on Logging for troubleshooting"

Click OK

Restart Outlook (you will see an annoying prompt each time you start Outlook, select to keep Logging On)

That's it, Outlook should stay synced now. 

this also worked for me. thanks!

It seems to be resolved for me by turning off all my rules (Home tab > Rules). When I turn them back on it reoccurs. But going by this thread, I think this error has multiple causes, which is why the solutions are so varied and unreliable. Good luck everyone.

I broke my rule of never using prerelease software - now I remember why I made this rule.

This appeared to do the trick for me.

Annoying to have the message at the startup of Outlook, but I'll take a single click if it means a syncing mailbox.

Hopefully the full release of 2016 will resolved this.

Thanks!