My outlook isn´t reading one folder. Maybe email size a large 1.5 GB or maybe files are corrupted I don't know. How to recover it?

Outlook didn't use dbx and well, there are spammers that will share dbx recovery apps. My favorite Outlook Express dbx recovery is from my backups. Then again I haven't had to do that in over a decade. So what next? Try Firefox and import the DBX. How is on the web.

Oh, and those spammers? They'll show up soon enough. You usually can spot them by the number of posts they made. 1 is a bad sign.

Use SysInfoTools DBX recovery tool and repair all corrupted DBX files as well convert the files into multiple formats such as EML, PST, MBOX, MSG.

To open the folder containing your *.DBX files, do the following in Outlook Express:
Tools > Options > Maintenance > click "Store Folder" button.
In the small dialogue box that opens, you will see a path that extends beyond the width of the text field which will be:

C:\Documents and Settings\<USER_NAME>\Local Settings\Application Data\Identities{long-ID-number}\Microsoft\Outlook Express

Right-Click in the field > "Select All".
Right-Click > "Copy".

Cancel your way out of all the open dialogs and CLOSE Outlook Express.

Start Menu > Run.
Right-Click in the run field > "Paste" > press Enter or click "OK".
Every folder that shows in Outlook Express, including folders that you have made into sub-folders under a master folder, will have a corresponding *.DBX file with the same name as the folder.
Or OE-Mail Recovery also can repair damaged DBX files.
Check it out... http://www.oemailrecovery.com/repair-outlook-express.html

Hi, Thank you for your time and great help. I really appreciate your feedback and I am very thankful for your time and support. Solved!
Many thanks.

Hello everyone,
Thanks to all for your useful and wise thoughts, hopefully this would be a great solution.