Hi,
Then, works for me. How (and when) do you access rcmail.env.messageid. Open the source of the page and search for "messageid" string it should be there.
The "when" got me: In the message list view I can use the "init" hook and during the runtime of this function the rcmail.env.messageid is available. The 2nd window opens and displays the message ID. Great!
Unfortunately the PHP hook isn't called when a message is being replied to. I proved that by dumping the message ID to STDERR in PHP and watching the Apache error log. Do you have any idea what to do in this case?
Daniel