Have you ever been reading an email message in which the lines are shortened and appear cut off? It's as if a hard carriage returns were inserted after eight or ten characters, creating a column of text reminiscent of a haiku poem, in which there are only a few syllables per line.
This problem is due to the different ways of representing text in different programs and contexts. Text as it appears in email can be in one of three formats: plain text, rich text, and HTML text. Plain text messages, in turn, can have flowed and non-flowed plain text. Flowed text is a form of text in which spaces play the role of continuation of paragraphs. Technically it was first defined in RFC 2646, later extended in RFC 3676.
The main point of flowed text is to display text correctly despite of the screen width of the recipient of the message. Depending on the size of the screen (or display window) of the recipient of the message, the displayed text may contain text wrapped in undesirable ways. This is a delicate point, especially in small screens (like a PDA, cell phone, etc). Normally when a text written in a 80 columns terminal is displayed in a 30 columns screen, lines are cut in the middle and the formatting of the message is destroyed. Vice versa, when a message was written in a 30 columns screen and it is displayed in a 80 column screen, the message feels like it was wrapped too early (the effect to which you refer as "haiku"). The purpose of flowed text is to be able to send and receive text that will adapt to the screen width of the display device (window or screen), no matter what device that is, so the same text will look well-formatted in a 30 or 80 columns screen.
The behavior of flowed text is such that resizing the display window also resizes the number of columns of text and the way it wraps. Flowed text will insert a new line only at the end of a paragraph, and as such multiple lines behave as a block. Non-flowed text (fixed column width) will insert a new line at the end of the defined last column, on each line. (Columns are defined as the number -or position- of characters on a line on the display.)
Flowed text will be interpreted correctly by programs and contexts that know about flowed text, as long as the reply quote string is either ">" or "> ". Observe that if you correspond with someone who uses a different quote string than the above mentioned strings and has an e-mail program that is aware of flowed text, then when you quote quoted text in their messages using either ">" or "> ", there's a very good chance that the message will look corrupted in the screen of the recipient, in the sense than the second level of quoting will look mangled.
A conflict arises between programs that understand and use emails composed as plain text (flowed) text, and also understand and use emails composed with rich text format (RTF) or HTML. HTML is quite another mess, but I won't get into that.
For example, Messenger Express (the web-based mail program in NYUHome), uses plain text for composing messages, but does not bother to use the flowed format. Therefore, it inserts hard line breaks at the end of each line. This means that the message may look OK in the composition window, but may and often does look different on differently sized screens (or display windows), displaying what you have noticed as the "haiku" effect.
What can be done about it? Messenger Express will compose messages in non-flowed (fixed width) plain text format, unless you use Internet Explorer for Windows. Other recent mail (desktop-based, not web-based) programs, such as Outlook and Mail, compose messages in flowed plain text format, however this problem still happens because different people reply to messages in different mail programs, some of which may mangle the line breaks upon reply, as explained above. Short of making everyone use the same mail program, to compose messages in the same format, there is very little that can be done about this.
I invite comments.
