I once had this problem. To solve it, I followed these steps:
Installed Microsoft Outlook on my PC
Configure the Google Mail Account (POP/IMAP) - for this, I suggest following the steps posted on Google How To
Imported the
.pst
fileDrag and Drop
I prefer this solution, because my .pst
file was too big (~4.6GB) to export to Google and I wanted just an attached file of one single message.