I am a parser for mail inboxes in a form found in the Unix '/var/spool' inboxes. This is also the format used by Eudora 3.0 on the Macintosh (and perhaps by other versions of Eudora as well).

	scanning
	delimitersDo: findPossibleMessageStart: mailMessagesDo: nextStringIs:in: scanToNextMessageIn:

	read-write	top
	readFrom: This operation is a noop for mail inboxes. Use 'messagesDo:' to enumerate the messages in the inbox.
	writeOn: This operation is illegal for mail inboxes.

	scanning	top
	delimitersDo: Invoke the given block for each message in the mail inbox. The block argument is the text of a new message.
	findPossibleMessageStart: Find the next line starting with the string 'From' followed by a space. Leave the input stream positioned at the character following the space.
	mailMessagesDo: Invoke the given block for each message in the mail inbox. The block argument is the text of a new message.
	nextStringIs:in: If the next characters of the given stream form the given string, then advance the stream position by the size of the string and return true. Otherwise, leave the stream untouched and return false.
	scanToNextMessageIn: Scan to the start of the next message in the given stream. Answer true if we find a message delimiter, false if we hit the end of the stream first. The stream is left positioned at the start of the next message or at the end of the stream.