You are using a fairly older API version and I suggest you to please try using latest Aspose.Email for Java 20.5 on your end. I hope this will resolve the issue. If you still face any issue, please provide the used sample code along with snapshot of the issue so that we may proceed further to help you.
Yes, I did resolve the problem. I created a contact item in Outlook containing a lot of fields and exported it to a .pst file. Using the API I read the contact item and investigated how all entities were set. No issue anymore. And I updated to 20.5. (Bit also using 20.5 before making any changes I got that funny display nme, presumably being the default setting by Outlook if left out in the generated .pst file.)
Again, thanks a lot!