Yahoo! Mail keeps changing and changing. The latest 'improvement' is Rich Text for the replies. But what if you want the standard email conversational tone of yesterday - in other words, commenting on a phrase by the sender which is easily seen an understood by the use of > symbols before each line. Like so:
> this is a test
> this is only a test
Perhaps there's a way to do it in Firefox, but I haven't been able to figure it out. Fortunately this style of email is still intact if you use Safari. So if you're like me and want those > symbols, use Safari.