Hi Rudi,

first of all let me know, what type of account are you using, is it POP3 or IMAP?

This type of problem occurs when you use POP3 account, because in POP3 configuration only allow you to download the inbox mail. To download all the Outlook items at once, you need to use the IMAP configuration.

While configuring an account into Outlook with IMAP configuration, make sure to use the correct IMAP settings of the same account that you want to configure with Outlook.

Thanks & Regards,
Anjlua