Batch rename files using Windows command line.
for /d /r %x in ("*") do pushd "%x" && ren *.eml *.msg && popd
Recently restored about 18k emails in various folders from a PST file which exports as an .MSG formatted file. I then reconverted those .MSG to .EML format. Now, the mail server I’m using requires .MSG extension but .EML format (go figure) so I had to rename all these suckers.
Easiest way was with some command line kung-fu. Luckily the ren *.eml *.msg works otherwise this would have been a bit more complicated.
I also had to rename all the folders and append .IMAP; this was accomplished easiest with:
for /d /r %x in ("*") do ren "%x" "%~nx.IMAP"
