An e-mail is classified as "formal" if you're addressed with your last name. If you're addressed with your first name, the mail is supposed to be "informal".
ReplyButler automatically detects this and adjust the answering phrase. If your cliptexts support this, the cliptext matching the formal/informal state will be used. (This is not very important for the English language, but very useful for some other languages.)
By default ReplyButler recognizes the style of the original e-mail (formal / informal) and imitates it when answering. But you can also configure ReplyButler to answer always formally (or always informally). You can to this in the options on the page "Phrases".
