Outlook reading pane slow to load for some emails

Hello RusselHeller,

Thanks for posting here.

I noticed your system is windows 7,  and the system requirement for Microsoft 365 and office are Windows 10, Windows 8.1, Windows Server 2019, Windows Server 2016(more details about system requirement, please check here), so please try to update your system to check if it will be better.

If issue persist, there are many reasons for outlook performance issue, many of these reasons can be automatically checked by the Microsoft Support and Recovery Assistant (SaRA). To start the automated checks, follow these steps:

1.    Install the Outlook Advanced Diagnostics tool.

2.    Click Run when you are prompted by your browser.

3.    In the report that’s generated, review the items on the Issues found tab. For configuration details about Outlook, Windows, and your computer, review the settings on the Detailed View tab.

More details please check Outlook performance is slow in the Office 365 environment  

In addition, I would like to know are there too many items or folders in a cached mode .ost or .pst file, it will also cause performance issue.

Please feel free to let me know how is it going, we will always be here to help you😊

Best regards,

Regina

Hello RusselHeller,

Greetings for the day, if you need further help, please feel free to let me know.

Best regards,

Regina

Thank you for your response Regina. I am working with my IT support to see if they can run the diagnostics and check the system requirements. I removed some temporary files last week which didn't change anything but where could I look if there are too many items and folders in a cached mode .ost or .pst file? And do I simply remove them once I find them?

I still strongly suspect the issue has something to do with the automatic download settings but why would emails from internal colleagues be more affected than emails from anyone external?

Thanks.

Hello RusselHeller,

Thanks for your reply.

Since we don’t support Windows 7 system, so I recommend you first update your system. Or change a device to see if this issue persist.

.pst is Outlook data file contains your messages and other Outlook items and is saved on your computer. .ost is offline Outlook data file, When your connection to the mail server is interrupted, you can still access all emails, calendar data, contacts, and tasks that have been previously downloaded.

How to find these files:

.ost: File->Account settings->Data Files.

.pst: File->Open & Export->Open Outlook Data File.

If your files are too large, you cannot simply remove them, please reduce size of PST file by the following method:

Split the large-size PST file.

Compact the large-size PST file.

Remove duplicate data from the large-size PST file.

In brief, please first try to change a system environment, because windows 7 is not a support environment, thanks.

Best wishes,

Regina

Hello RusselHeller,

If you need further help, please feel free to contact me.

Best regards,

Regina

Some emails that I receive are slow to load in the reading pane, about 30+ seconds, when I click on them in my inbox. It only happens with emails received from internal colleagues, emails from any external email address have no issues.

If I click reply all, I can then also immediately read the email in the draft that opens.

It's been going on for a few months now and my IT support is stumped. I've also tried different options with the automatic download settings but nothing seems to be able to get me back to the way it was originally operating.

I'm using Windows 7 and Microsoft Outlook for Office 365. Thank you.

We are also experiencing the same problem.  It is only affecting internal co-worker emails.  All outside emails load instantly in the preview reading pane, but any email sent by anyone of our staff takes a long time to load in the preview reading pane.  This issue just literally started happening as of last week.

How to fix?

We are having the same issue with internal co-worker emails.  I've tried everything, safe mode does not resolve the issue for us.

Curious with other users having this problem, are any of you using a signature manager?

Regina, 

My company is having the same exact issue described here and we are using Windows 10. The issue is only on internal e-mails that are sent. We have tried everything that we can think of including all of your suggestions above and have still not found a solution to this problem. The issue seems to only be in one group in the company and began when the department switched to Windows 10 Intune managed systems. Ever since then, the issue has persisted. Any help would be appriciated.

Thank you,

Adam Smith

We are facing the same issue with emails from internal colleagues, we are using windows10 with O365,Office2016 or 2019. I have observed that this issue occurs only with those users who has uploaded their profile pictures in teams. Exiting teams and opening it again partially resolves the issue. It reoccurs at any point of time. Hope MS fix this soon.