Exchange/Outlook 2019 delete emails by date

Question

Exchange/Outlook 2019 delete emails by date

Susan Dodds 421

Exchange 2019, Outlook 2019,

I have someone that wants to delete all of their email prior to 2026.

What's the easiest/fastest way to accomplish that without deleting each email manually?

I am doing a PST export from Outlook before proceeding.

Mailbox is around 20GB.

Thanks

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2 answers

Your answer

Answer 1

The fastest supported approach in Outlook 2019 is:

Finish the PST export first so there is a backup copy.
In Outlook 2019, create a Search Folder or use search to find mail by date.
- A supported Q&A approach is to create a Custom Search Folder and set the condition to a fixed date/year, then use Ctrl+A to select the results and Delete.
If the goal is to remove everything before 2026, search for older mail and move or delete it in bulk.
- In Outlook search, date-based filtering is supported in similar guidance such as received:<01/01/2022; the same pattern can be used to target older mail.
After deleting, empty Deleted Items. Mailbox space is not fully reduced until items are also removed from Deleted Items.
If the Outlook data file remains large after deletion, compact the .pst or .ost file, because Outlook data files do not always shrink automatically.

A practical workflow for a 20 GB mailbox is:

Export to .pst first.
Search for mail older than 01/01/2026.
Select all matching items with Ctrl+A.
Delete them.
Empty Deleted Items.
Compact the Outlook data file if needed.

Notes:

Exporting to .pst makes a copy of the mailbox data; it does not remove the original items from Outlook.
If Cached Exchange Mode is in use, exports may only include items currently in cache unless adjusted.
Deleting large volumes of mail is potentially destructive; confirm the PST backup is complete before bulk deletion.

References:

Answer 2

Ruby Nguyen 1,480 Independent Advisor

Good day Susan,

Since you have already exported the mailbox to a PST file, the easiest and safest approach is to search for emails received before January 1, 2026, review the results and then delete them in batches.

Additionally, please note that Exchange Server 2019 has reached its end of support. Microsoft no longer provides security updates, bug fixes, or technical support for this version.

Here are some options you can consider:

Option 1: Use Advanced Find (Recommended)

Open Classic Outlook.

Select the mailbox or folder you want to clean up.

Press Ctrl + Shift + F to open Advanced Find.

Go to the Advanced tab.

Select Field > Date/Time Fields > Received.

Set the condition to on or before.

Enter December 31, 2025 and select Add to List.

Select Find Now.

User's image

Review the results to confirm they only contain emails before 2026.

You can press Ctrl + A, then right-click and select Delete.

User's image

Repeat until all matching emails are removed.

Perform the same steps for other folders if needed.

After confirming everything is correct, empty the Deleted Items folder to free up mailbox space.

Option 2: Outlook Search

Click the Outlook search box.

Set the scope to Current Mailbox > Select Advanced Search.

Search for emails received before January 1, 2026.

Review the results.

User's image

Press Ctrl + A, then right-click and select Delete.

Empty Deleted Items after verification.

Additional information is available in the following resources:

Find a message or item with Instant Search | Microsoft Support

Search and filter email | Microsoft Support

Option 3: Exchange administrator cleanup

If you prefer an administrator-led approach, Exchange Server provides tools to search for and remove messages that match specific criteria. This method requires the appropriate administrative permissions.

Note: If you don't have sufficient administrative permissions, please contact your Global administrator for assistance. In case you do not know who is your Global admin, kindly refer to this article: How do I find my Microsoft 365 admin? - Microsoft Support

For more information, please refer to this article: Search for and delete messages in Exchange Server | Microsoft Learn

For safety, it is best to run the search first, review or export the results and then proceed with deletion only after confirming the correct messages have been identified.

Note: Compliance Search deletion isn't recommended for this type of mailbox cleanup because it is designed for incident response scenarios and has deletion limitations per mailbox.

I hope this information is helpful. Thank you for your patience and understanding.

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Susan Dodds 421 Reputation points

2026-09-06T03:19:42.77+00:00

Thanks for the reply.

I'm still working on the PST export at the moment. Is it normal for the PST export to be less than half the size of the mailbox?
Ruby Nguyen 1,480 Reputation points Independent Advisor

2026-09-06T13:46:07.5666667+00:00

Hi Susan,

Thank you for the update.

This is normal in many cases because the mailbox size shown in Exchange or Outlook and the PST file size are calculated differently. The mailbox size can also include items that aren't exported, such as content in an Online Archive, deleted items, or data that hasn't fully synchronized to Outlook.

Once the export finishes, please check the following:

Open the PST file in Outlook.

Confirm that the expected folders and date range are included.

Compare key folders such as Inbox, Sent Items, and any custom folders with the original mailbox.

Verify that the export completed successfully without any errors.

The best way to confirm the export was successful is to compare the folder contents rather than the file size alone.
Susan Dodds 421 Reputation points

2026-09-07T15:24:01.24+00:00

Reran the PST export and it's closer in size to the mailbox.

Mailbox size is 23gb as reported by the Exchange management console.

First PST was around 9gb. New PST is around 20gb. .

Looking like everything is in there so I'll start purging later today most likely.
Susan Dodds 421 Reputation points

2026-09-07T16:14:53.96+00:00

The advanced search only loads about a month at a time. I need to delete 16 years worth of emails.

Is there a faster way?
Ruby Nguyen 1,480 Reputation points Independent Advisor

2026-09-08T09:29:25.9433333+00:00

Hi Susan,

I'm glad the new PST export is much closer to the mailbox size and appears to contain the expected data.

I understand that deleting emails accumulated over 16 years can be time consuming. However, processing a very large number of messages at once can impact performance and cause Outlook or the device to become unresponsive. To keep the process stable and manageable, I recommend deleting emails in smaller date ranges, such as one year at a time.

Please follow these steps:

Open Outlook and go to File > Account Settings > Account Settings.

Select your Exchange account and choose Change.

Set Download email for the past to All.

Restart Outlook and allow synchronization and indexing to complete.

Press Ctrl + Shift + F to open Advanced Find > Go to the Advanced tab and follow the steps previously provided.

Search by Received date and filter a smaller range, such as one year.

Delete the returned messages, then repeat for the next date range.

After confirming the emails are no longer needed, empty the Deleted Items folder.

Using smaller date ranges helps Outlook return more complete search results and reduces the risk of performance issues during the cleanup process.

I hope the process goes smoothly. Please let us know if you need any further assistance.