pst and ost folder/ number of mails is visible by Inbox but do not show

After Software update my e-mails do not show up in my inbox under my account. Sent mail I can still see. I can also search and find my mails.

I can find an ost. file with the myaccountname.com(2) under the acount settings/data files. It looks like the (2) is the problem but I cannot find any way as Outlook only seems to recognize .pst files.

How can I correct this?

Thanks