Well, things become simple if you have VeryPDF docPrint PDF driver installed in your computer when you want to print Outlook Express document to PDF file. VeryPDF docPrint PDF driver is a virtual printer which is contained in many VeryPDF document converters like VeryPDF PDFcamp, VeryPDF docPrint, VeryPDF docPrint Pro. You can download a free version of any of the mentioned veryPDF products from the following website: https://www.verypdf.com/
After you have installed one of the VeryPDF products, VeryPDF docPrint Pro, for example, you can revoke VeryPDF docPrint PDF driver to print Outlook Express document to PDF file in the following way:
Step 1: Open the Outlook Express document in MS Office. You can open it by double clicking the icon of it; or right click the icon, and select [Open] on the drop down menu to open the Outlook Express document you want to print.
Step 2: There are two methods for you to open the [Print] dialog box: Method 1: You can press [Ctrl+P] on the keyboard. Then, you will see the [Print] dialog box as illustrated as following.
Method 2: You can click the [Print] button on tool bar of the Outlook Express widow. 
Then, the [Print] dialog box will appear on the computer screen.
Step 3: To call docPrint PDF driver, you should select [docPrint PDF Driver] as the printer in the [Select Printer] list box as illustrated above, and then click on the [Print] button. You will see the [Save As] dialog box appear on the screen as illustrated below:
Step 4: You should type the name for the file printed from Outlook Express document to PDF in the [File Name] edit box; and then click on the [Save] button. As soon as the [Save As] dialog box disappears from the computer screen, you will see a printer icon
appear on the task bar down the computer screen. This means that it is printing Outlook Express document to PDF file. At the same time, the PDF file is saved in your computer. The process will take five or more seconds, depending on the size of the source Outlook Express document. When the conversion is finished, the newly created PDF file will be open by default.
The following is the comparison between the original Outlook Express document and the output PDF file. As you can see, the contents are well preserved from Outlook Express document to the output PDF file.
Before: the original Outlook Express document:
After: the output PDF file:
