Thunderbird is a pr0ogram running on your computer. Not a web site. So really I have no idea what you even mean by a blank page. You install it, set it up with your mail account details and when you open it , it reaches out to your mail provider and gets your mail.

What is this blank screen?

I'm well aware of that - there's no need to sound so condescending. I was looking for a way to open without the "Choose what to set up" and "Import From another program" info - both of which are quite valid and useful, but not necessary to show every time the program is opened. If it's not possible, why not just say so, instead of just assuming that the user is an idiot?

Go to Help > Troubleshooting Information > Application Basics > Profiles > about:profiles. Launch the others one at a time and restart TB. If they all give the setup screen, try creating a new profile (https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-thunderbird-profiles).

Thanks for your very helpful suggestion Ed. I have several profiles in the account and after the rude and unhelpful response from Matt I tried a couple of things and found one way to get TB to open how I want was simply to leave a profile message screen open when I closed the app. That way it reopens there and I can just switch to the one I want, which is pretty close to the way WLM works. That's probably the same, or at least similar, to your suggestion and I'll have a look at that later tonight - it's been a long day :-) Appreciate your help.