If you have used the Send exclusive feature to share content from Mynewsdesk, you may want to check and follow up on these emails. 

You can find this piece of information under Analyze > Your content. Since this overview shows only published content by default, you’ll need to change the filter to show Draft items instead. To find it even faster, you may also filter on the publication type, e.g. Press release. 

Then click on the heading of the publication in question. Go to the tab Email reach, then Sent exclusively.

In the case that you want to have a more detailed look at particular contacts, you can always check the full list of all emails sent to them (incl. Send exclusive messages) by looking them up under Contacts > Contact lists.

Please also see:
Can I share content without publishing it?
Analyze specific content
Introduction to Contacts