You can drag and drop the email file into a container field. This does not produce something that you can read without opening the file, however. you could select and copy the text contents of the email into a text field. There may be an email plug in that offers other options for supporting this.
Container fields are limited to one file per container field. But you can link an unlimited number of container fields to a single record if you set up a related table of records with one container field to a record.