I do my work on Macs, so the below procedures apply to Macs.
I use Thunderbird to get my emails, and I organize emails into folders. To print all emails in a folder, I have found that if I select a bunch of emails, Thunderbird only prints summaries of the emails. So I've been exporting all emails as a .mbox file, then bringing that .mbox file into Entourage 2004 (part of Microsoft Office for the Mac up to version 2008). Entourage then can print all selected emails as a PDF, rather than just a summary of the emails.
To extract separate emails from the long PDF, I use an old, old version of Adobe Acrobat. It still works on my Snow Leopard machine, which is kind of amazing, but it is old and clunky. Buying a new version seems wasteful since the program is expensive, I don't use the program all the time, and I know that there are alternatives out there. I try not to use or buy Adobe software if at all possible, because I have had so much trouble with their registration and activation of licenses for software, and in trying to transfer software licenses when I buy new computers.
My friend and computer expert Michael McFann suggested this instead:
"If the task is to simply extract pages from an existing PDF file, then OS X's built-in app "Preview" will allow you to extract one or more pages from an existing pdf.
For example, I have included a document on Facebook security and a second pdf that has just one of the pages from the original pdf file.
The trick is to make sure you display the sidebar which displays the page thumbnails and simply drag/drop the pages. You can also combine pdf's this way. "