Hi Danjel,
As I understand, you have created a user mailbox in Office 365, then you deleted the account and re-created one. Now the new created account can only send email, can’t receive email if sender send email to the account. Please correct me on time if I misunderstand the issue.
If so, please delete the auto completion in Outlook Web Access (OWA) to see if the issue persists. Please follow the steps below to delete the auto completion in OWA.
1. Login Outlook Web Access (OWA) using this account.
2. Click New>Message.
3. In the To box, start typing the name or email address that you want to delete until you see it appear in the AutoComplete list.
4. To remove one entry from the list, highlight the name in the AutoComplete list by using the Up Arrow or Down Arrow keys.
5. When the entry is highlighted, press the Delete key.
6. After that, completely retype the recipient's email address (not display name) again in the To box, then send the email out to see if the user could receive this email.
Thanks,
Eric Sun