Automatically forward and rename .eml attachments to .txt


New Email
I receive a number of emails every day of the Lefsetz Letter. I want to be able to read them on my new Kindle Wi-FI (4th Generation). I want to automatically forward the emails to my Kindle email address. The problem is that they are forwarded as .eml attachments, which the Kindle can't read. It can read them if I simply manually change the file extension from .eml to .txt. I can't find any way to automatically forward these emails as attachments and automatically change the file extension to.txt Any ideas on how I can do this? I use a Gmail account with Thunderbird as my email client. - Thanks