You have 1.3k msg files? Don't you mean you have 1.3k emails in a msg file?
The easiest way to do this is with the Acrobat add-in for Outlook.
Open outlook and look for the Acrobat tab
There are also some MSG to PDF conversion utilities online
- Zamzar.com - zamzar.com/convert/msg-to-pdf/
- CoolUtils.com - coolutils.com/online/MSG-to-PDF
I don't know anything about them.
I have 1300 separate .msg files saved in a folder on my computer. These are not in Outlook.
The Outlook program is not a 'stand alone' program, but on Microsoft Exchange with DMS integration.
If outlook doesn't work for you, then try one of the online tools in my previous email.