I've gone through my "Sent Items" folder after my Scalix 10 upgrade, and noticed something weird. Some emails do not show an entry under the "To:" coloumn in Outlook. I went to SWA and found that the entries are correctly displayed there.
So I went back to Outlook, and found the following:
It's all emails that was sent to external recipients where I just typed the address into the email, without selecting it from the Contacts. Not all of them do this, though, some show up correctly.
I then opened the emails themselves, and saw that the ones that display correctly (have the email address in the "To:" coloumn have quoted email addresses. Outlook displays it as
To: 'email@address.domain'
while the ones that are not displaying correctly seems to be unquoted
To: email@address.domain
If I double-click on the address to let Outlook display more details on it, there doesn't seem to be a difference in display.
All the emails that are affected have oriniginally come in from outside people, where their local mailers doesn't attach a comment to the address, and to which I've then replied. If I sent the original message, it seems to work fine.