Comment 20 for bug 849624

What to do with all the permutations of command lines is complicated. If you're looking for a way to have an icon on the desktop that starts Thunderbird in Lightning mode, then it doesn't seem like you need to worry so much about other command line arguments...but if you're looking for how to handle it in all situations, I'm not sure that 2 messenger windows isn't the way to go. If I launch TB with -calendar and a .eml file, you'd want two windows, right?

I don't know what you mean by starting TB with a start page on the command line - that doesn't do anything. You can launch Thunderbird with a uri for a message, which loads that message, or a .eml file, which loads the .eml file. Conceivably, you could have a uri for a folder as well, to startup with that folder. But a start page doesn't do anything, afaik.