I was not aware that firefox was only a browser.
You are not the only one, but not as bad as the many people who thought that NS8.x and 9.x, all nineteen, or so, versions that because they carried the name Netscape, they had to be similar to the 7.x versions, which were suites of Browser, Mail, and Composer, at least.
However, perhaps to battle the Microsoft applications on more even terms, the standalones came out. Firefox to be equivalent to Internet Explorer, Thunderbird, to be equivalent to Outlook Express. And Komposer as a....composer. One needs three different applications to equate what one was doing. Seamonkey is a darned good application, and I hope that the small group of developers will carry on the old tradition with Seamonkey2.0, which blends a lot of Firefox, with the old ways. Seamonkey 2.0 has come out with nighlies, at least six months ago, and has not left the starting gate.
But, although our friend Richard is so used to have both Firefox and Thunderbird, they still are separate applications. But, it does not matter.
UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.14) Gecko/20080404 Firefox/2.0.0.14