Yep - you can save all of your business Outlook emails and attachments to a local hard drive before closing the account. On Windows, the most complete way to do this is by exporting your mailbox to a PST file. A PST file preserves your emails, folders, attachments, calendar, and contacts so you can reopen them later in Outlook even after the account is closed.
In Outlook for Windows (classic desktop version), open Outlook and click File, then Open & Export, then Import/Export. Choose “Export to a file,” click Next, select “Outlook Data File (.pst),” and click Next. Select the top-level mailbox for your business account and make sure “Include subfolders” is checked so everything is captured. Click Next, then Browse and choose a location on your local hard drive or an external drive. Give the file a clear name such as BusinessEmailArchive.pst and click Finish. If prompted, you can set a password or leave it blank.
After export, verify the file exists on your hard drive. In Outlook, you can test it by going to File, Open & Export, Open Outlook Data File, and selecting the PST file. It should open as a separate data file in your folder pane so you can confirm all emails and attachments are accessible.
If you want attachments saved separately in regular folders (outside of Outlook), you would need to open the PST and manually save attachments, or use a third-party bulk attachment extractor. Outlook itself does not provide a built-in one-click option to export all attachments separately.
If you are using the newer Outlook app that does not show the Import/Export option, you may need to install and use the classic Outlook desktop application to perform the PST export. Make sure the export is fully complete and the PST file is backed up to at least one additional drive before closing the business account, because once the mailbox is deleted, you cannot re-export the data from Microsoft’s servers.
As long as you keep the PST file and have Outlook installed on a Windows computer, you will be able to open it in the future to search emails and access attachments for client reference.
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hth
Marcin