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Feb 28 2024 07:00 AM - Feb 29 2024 10:30 AM (PST)
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Outlook not updating inbox

Copper Contributor

I have added a second mailbox to my outlook. It will update when I start in the morning but last email will be like 9 am & will not update again unless it wants to. I have reconnected, shut down outlook, & can not get it to work. On my phone it works fine but on the pc it is like it has a option to check every 8 hours & will not check any other time.

32 Replies
Hi try to turn off Cached Exchange Mode, please perform the following steps:

1. Click File > Account Settings > Account Settings.

2. Click the Office 365 account, and then click Change.

3. Under Offline Settings, uncheck Use Cached Exchange Mode.

4. Exit, and then restart Outlook.

I tried that & no change. I will see if it does anything after a full computer shutdown & restart

The root of the problem may be that the second account has a large number of folders >500 will cause a problem with the OST file, it cannot handle more then 500 folders (in all accounts in this current profile) and this is why turning off cached mode may help.  Removing this 2nd account may also correct this issue.  It is a known limitation within the outlook client.  Be aware that not running in cached mode may present performance issue if the mailbox is large or connected over a slow connection

Yep, I think we need more info. on the accounts he wants to add to Outlook...adding a second or more accounts should not be a problem

@Thuyavan Ganesan worked perfectly, thanks a ton!

I am having trouble with my email not syncing to outlook.  I tried going to Account Settings/Account Settings/selecting the email file and then clicking change.  The box for "use Cached Exchange Mode to download email to an Outlook data file is greyed out so I cannot uncheck it.  Any other suggestions?


Outlook was working before.  I had to totally restore and load all of the Office 365 programs back on.  Ever since then, It has quit working.  Also, I only have an .ost file.  There is no .pst file.  My old .pst is backed up on an external drive.  Do I need to save on my PC and link back to outlook?  If so, I don't know how to do that.



@BNC173If you have recently updated, your emails may be filters by read/unread.

@options38 I am having the same issue. Outlook was working fine for months, with no issues and now its not updating my emails. Ive tried repairing both the accounts that I use, which did work for a bit, however its no longer working. I assume it was an update to outlook thats just broken? Every time I launch outlook i need to repair the accounts. 

My solution might be too simple for the problems mentioned.  However, here is what I did.


1. Went to Start Box and entered Task Manager

2. Selected Task Manager app shown.

3. Selected Outlook from the running apps shown

4. Entered Quit Outlook

5. Restarted Outlook


That fixed my problem. I think it occurred from emails being open with attachments never being closed.



@Thuyavan Ganesan 

I have no Offline Setting in Office 365.

How can I find it?

I think it is more indicator than setting. If you disconnect from the internet look in the ribbon at the top of the screen on the right side. You should see the offline indicator.
Since my user never had any issues, I concluded the above fix might be the most plausible one. I went through the various steps Rob42 indicated, and the problem disappeard.

I did this and now I can't open the PC app at all because it can no longer find the files. 

@Thuyavan Ganesan 

None of those fixes worked for me. After 24 hours, I realized my inbox had stopped updating after I had a large file (40Mb) undelivered. I deleted the returned email and Hey Presto! The inbox updated immediately.
This is one works to me! Thank you for your help!

@Thuyavan Ganesan 

thanks, worked like a charm!

@rob42 Thank you for your reply.  That is pretty much what I have done.  It is frustrating as ordinary users should not have to take these steps.

@Thuyavan Ganesan 


Your Response worked for me thanks






@Thuyavan Ganesan After I made the change just restarted outlook, Worked perfectly! Thanks!