Problems importing email from Outlook 2011

I have spent many hours now trying to move hundreds of emails from various folders I have in Outlook 2011 into a database in DT. Many of these emails have attachments and many of those attachments are PowerPoint files - some as large as 3-5MB. I have run into numerous issues. From running out of memory to an error message that says I need to finish downloading an item in one of the folders I want to import. (I have no idea what that means.) I have tried only doing a couple hundred at a time. But I am almost about to give up.

I also tried just dragging and dropping emails into the DT database. I don’t know how these processes will be different. But I do know that after dragging over an email with a 3MB PPT attached I was unable to open the attachment in PPT. Similarly I was unable to open a .DOCX file (Word.)

Anyplace I can go where there are detailed instructions on how to move email from Outlook 2011 into DT w/ attachments?