e-mail open is too slow when an e-mail has 3MB size within its text contents

Question

Dear all,
Our colleague is using e-mail as a historic archive, so their e-mail has pretty large contents and it is about 3MB.

If I click on a file that is only about 3MB in the body of the email in M365 Outlook, it takes a lot of time to load.
It loads quickly in the online version of Outlook (https://outlook.office.com/), but I want to know why it takes so long in Windows Outlook.

We are using M365 Outlook version. "Microsoft® Outlook® for Microsoft 365 MSO (Version 2207 Build 16.0.15427.20166) 32-bit "

I think this is from some validation check of e-mail or security check.
Please help this issue for our colleagues.

Answer 1

Hi @Ouk Choi ,

Welcome to our forum!

Does this issue occur with the 3MB email or all emails?
And do you mean open the archived email or just open email in Inbox folder?
In order to further confirm if the issue is related to your Outlook client, please configure your account in Outlook in other computer to check if the issue still exist.

If the issue only occurs in your Outlook desktop client, do you have a large .pst file or .ost file?

As i know, if you have a large .pst or .ost file, you may experience application pauses while you perform typical operations in Outlook. These typical operations include reading, moving, and deleting email messages. Please check the size of your mailbox via File>Tools.

If the your mailbox is not large, considering the impact of some add ins, It is suggested that you try to start outlook in safe mode (win+R>type: outlook /safe) to check whether it works normally.

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