I'm planning to do some backups of my e-mails in my yahoo account.
I'm afraid to do it using Outlook or Thunderbird, and be "locked" to their formats. I know Thunderbird is Open Source, but I don't know if it's format specification is a standard one, and just because it's open source doesn't mean it would be easy to recover data in the future.
Does exist a standard format specification to e-mails downloaded from POP3 accounts, that I would be able to read/open without specifically opening the e-mails accounts?
Each file would be an e-mail, with metadata as data received, attachments, and such.