"EML" is nothing more then a usual convention on the file names used by many e-mail applications and some Web browsers (like Mozilla Seamonkey suite which does not use it in its e-mail application but view them). Those files do not have any special file format. The simply have all the data which is contained in the e-mail message, as a package sent and received by Mail Delivery agents (
http://en.wikipedia.org/wiki/Mail_delivery_agent[
^]), POP3, IMAP servers, etc.
If you simply open this file with a text editor, you will have a pretty good idea what's in it: headers and, optionally, some "parts", in a multipart messages. You might wish that some of the parts could be presented to you in a more human-readable form, such as HTML, but you did not tell us what would you like to do with it.
If try to find "attachment", you will see that there is nothing which is "attached"; an attachment is merely yes another message part embedded in the message (so I don't know why it was called "attachment", perhaps by some historical reasons) with "Content-disposition: attachment" and optionally, a file name:
http://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html[
^].
Basically, it is designed to include arbitrary file in arbitrary formats. E-mail programs usually offers a possibility to "save" them as separate files. I wonder what would you mean by parsing them, so not parsing "attachments" is probably the only reasonable option.
To parse a message into its components, try to use this MailUtilities library:
http://mailutilities.codeplex.com/[
^].
—SA