How to batch print multiple e-mails into one single PDF with one click on Windows 7?

Question

I use the e-mail software "Postbox 2" and I won't switch this so fast, as I have like 7000 e-mails in my GoogleMail account, which is the main account I want to print the e-mails from.

I'm going crazy, I already searched around for over two hours and tried like six different free and paid PDF printers, including my own(ed) Microsoft XPS, Microsoft OneNote, Adobe Acrobat and Bluebeam Revu!

Actually the one option I found was PDFCreater, but the v.1.2.1 keeps crashing when I try to put e-mails with initially large attachments in the waiting/print queue! :( I will report it soon to their forums. So this one candidate is out, even though promising...

Most of those PDF printers/distillers (?) have the ability to batch process any kind of document into one PDF file with (more or less) one click, but not e-mail, never?! I mean I always used the print dialogue, yes. But there is no other option, except maybe to save / export those e-mails! Do I really have to do that? (Didn't think about it, but maybe at least this can be done with one click...)
I know there is a solution for Excel files, but we're not talking about Excel, but e-mails.

I mean something like "Actions" (never used this before) might help, but only as I want to save my e-mails per month (so I don't want one PDF per year or so, but several dozen e-mails or like half a dozen threads still into one PDF), "Actions" will only help when I can initially produce the results once, which I can't. I mean I not only want to initiate the printing process with one click, but also only one click on "save", because I want it to generate a PDF with e-mails within sorted (ideally reversely) by date.

Again I can merge afterwards (either PDFs or *.eml files or whatever the file ending), but is there really no alternative to it? The only option to properly sort this out later would indeed be to use a PDF processor like Bullzip PDF Printer, which actually offers to batch rename (i.e. after date) PDF files while converting them.

Hope I was not too stubborn with this, but I wonder why this is not possible in 2011?