IMAP4, commands, data items

1 LOGIN email pass1
EXAMINE INBOX - select current dir
1 SEARCH UNSEEN / ALL / etc.
1 FETCH 10 (RFC822) - whole message


1 FETCH 10 (RFC822.SIZE) - size

1 FETCH 10 (BODY[HEADER]) - Full header

1 FETCH 10 (BODY[2.HEADER]):
1 FETCH 10 (BODY[2.MIME]):

Without attachment

Content-Type: text/html; charset=utf-8
Content-Transfer-Encoding: base64

OR

Attachment exists

Content-Disposition: attachment;
    filename="IMAG0067.jpg"
Content-Transfer-Encoding: base64
Content-Type: image/jpeg;
    name="IMAG0067.jpg"

1 FETCH 10 (BODY.PEEK[HEADER.FIELDS (Date To Cc From Subject X-Priority Content-Type Received Date Subject From Priority X-Priority X-MSMail-Priority Importance Precedence)])


1 FETCH 10 (BODY[1]) - visible mail text
1 FETCH 10 (BODY[1]<1.1024>) - partial content

1 FETCH 10 (BODY ENVELOPE) - represents envelope structures of the message.

http://www.apps.ietf.org/rfc/rfc2062.html
http://www.apps.ietf.org/rfc/rfc822.html