Access doesn't support drag and drop natively ... you can add controls to Access which may support drag and drop, but you cannot, for example, drag an Email onto an Access form and have it recognize this event.
That said, you can drop some things into a Table field, if it's a memo or text field, but you'll only get portions of the drop ... for example, if I drop my most recent spam email about Oprah's Superfood, I get this:
From Subject Received Size Categories
offers [SPAM-LOW] Oprahs Superfood of the year! Thu 2:50 PM 7 KB
Which is, basically, the header you see in preview mode in Outlook. If I show the email in preview mode, select All and then drag/drop directly to a Memo field I get the basic text of the email, but no header information.
I was NOT, however, able to drag a "file" into my table ... for example, if I select an Excel file and try to drag/drop it directly into a Memo field, Windows wouldn't allow me to do that.
FWIW, I have this functionality built into one of may apps, and I had to use 3rd party controls to do this. I used these:
http://www.ssware.com/These controls support drag/drop and I was able to allow users the ability to do exactly what they needed, and also build a neat Explorer-like interface with them. there are other controls out there which do this, just make sure they are supported in the Access environment.