It used to be quasi-standard that email and Usenet messages were to be limited to 80 columns or fewer—preferably with some slack (e.g. lines being 72 characters long) so that they could stand a couple of levels of quotation without exceeding the 80-character limit.
Later, people started to post with longer lines—either with a longer line limit (say, 100 characters) or simply without line breaks at all, assuming that everyone's reading software would line-wrap automatically. This occasionally produced some ire among the old-timers.
So, given that many people seem to want to use long lines, perhaps because display resolutions are increasing—why is it that email sent through the Yahoo! web interface seems to wrap at around 50 characters?
It seems strange to me that they would put out something with less than 80 characters per line nowadays. Why is this? Is their screen so full of advertising that wider boxes wouldn't fit in? Is the font too big? Do they only have 5/8 size punch cards in the big mainframe in the back?