we are observing a weird behavior of Outlook 2013 with ZCO 8.0.6 installed. It is not related to Outlook 2010 or 2007. If a user of Outlook 2013 sends an e-mail to a distribution list, Outlook expands the DL to its members and sends e-mail with all the members in "To:" field instead of sending e-mail to the distribution list itself.
I have been digging a little into it and noticed that only Outlook 2013 users right after installation and configuration of ZCO can immediately use the autocomplete feature of Outlook. For example here in the picture you can see that I can send email to "faktury" distribution list which I have never send anything before.
I have run a tool nk2edit for viewing the autocomplete cache and found out that among regular SMTP addresses the cache is full of our distribution lists and they are of type MAPIPDL which means MAPI Private Distribution List. See the picture.
And of course if this is Private Distribution List then Outlook properly expands the list to its members before sending because it believes that server does not know the list. I have check Outlook 2007 and 2010 installations with nk2edit and their cache does not contain the MAPIPDL items.
So the question is why ZCO fills the cache with distribution lists? Why it does that only in Outlook 2013 and why the entries are of type MAPIPDL and not simply SMTP.
Does anybody know something?