This browser is no longer supported.
Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(236.8, 41%, 32%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EPG%3C/text%3E%3C/svg%3E)
I use the online version of Microsoft Outlook for emailing. I would like to know how to back up my emails. Thanks.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(67.2, 19%, 16%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ESK%3C/text%3E%3C/svg%3E)
Do you mean you're using a browser?
Save each email locally as an eml file.
If you're using Outlook on the Web, talk to your organization's IT administrator and ask them to create an online archive.
If you have Classic Outlook, you can create a local PST file just for archiving.
My email address begins with the following: https://outlook.office.com/. I guess that means I'm using Outlook on the Web. Regarding your answer "If you're using Outlook on the Web, talk to your organization's IT administrator and ask them to create an online archive.", I am self-employed and have no IT administrator.
Thanks.
It is not possible to determine from that URL whether it is for an individual or an organization.
Isn't it the same as ? https://outlook.live.com/
Please download each email as an eml file.
Then install an app that can read eml files.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(121.6, 11%, 21%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ECM%3C/text%3E%3C/svg%3E)
Hi @Peter Glass ,
Are you using an Outlook.com account?
Hi @Peter Glass ,
I am writing to see how everything is going on with this thread. Should you need more help on this, you can feel free to post back.
Hello,
I apologize for not replying sooner.
Let me give you a few more details about my problem. I get my emails online through outlook.office.com. But I also get the same emails in the Outlook program on my computer (I have Microsoft Office Professional Plus 2016).
Every month, I back up my emails using the Outlook program on my computer and save the backup as a .pst file. I've noticed that even though I'm constantly saving new emails, the size of my backup decreases at times. Here is an example: On Feb 4, the size of the pst file was 2,254,089 KB. A few minutes later, without making any changes to the number of emails, the pst file decreased in size to 687,225 KB. And the strange thing is that four days later, after having added and deleted many emails, the size was exactly the same as it was four days earlier - 687,225 KB.
Even if you delete emails stored in a PST file, it simply marks them for deletion, does not reduce the file size.
The file size can only be optimized if the PST file is compressed.
The issue you reported is likely a corrupted PST file.
Are you saving your PST file in a folder managed by OneDrive?
If so, the PST file may be corrupted.
Also, if you're syncing with OneDrive, it's possible that it has been replaced with the contents of a PST file from another device.
I think you need to find an uncorrupted PST file and save it in a location that is not affected by OneDrive, and then check the legitimacy of the PST file.
<Japanese>
PSTファイルに保存しているメールを削除しても削除マークが付与されるだけでファイルサイズは減少しません。
PSTファイルを圧縮した場合にのみファイルサイズが最適化されます。
申告された事象だとPSTファイルが破損している事が考えられます。
OneDriveで管理されているフォルダ内にPSTファイルを保存していませんか？
その場合は、PSTファイルが破損する可能性があります。
又、OneDriveにて同期させている場合は、他端末のPSTファイルの内容に置き換えられた事も考えられます。
破損していないPSTファイルを探し出して、OneDriveの影響を受けない場所に保存して、PSTファイルの正当性を確認する必要があると思います。
I am saving my files only to a folder on my computer.
I back up my emails using the Outlook program on my computer and save the backup as a .pst file. I've noticed that even though I'm constantly saving new emails
What are the specific steps you take? If possible, please provide a detailed explanation with pictures.
Hi @Peter Glass ,
Welcome to our forum!
I use the online version of Microsoft Outlook for emailing.
Are you using Outlook for web or New Outlook for Windows?
And what's your account? An Outlook.com or anything else?
If you are using an Exchange online account, agree with simo-k, you can use the Exchange Online Archiving feature when your administrator enables the feature for you. More information:
Hope the above help!
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.