I am planning to backup emails in a mailbox to files. I am trying to find out the right format based on the following conditions:
- Should be readable/creatable without needing a particular OS - so Outlook file formats are out.
- Should support attachments. (Base64 Encoded is fine)
- Should be reasonably standard (I don't want to back up 5 years of emails before realising there are not clients around to read or process them.)
- Should be possible programatically possible to backup using Crons.
In all likelihood I will code the backup script myself using PHP as the language, but anything that works out of the box on Ubuntu is fine too.
It seems that MBox (https://en.wikipedia.org/wiki/Mbox) seems to be the right option. Is that so? If not what else? If so, any pointers to libraries that operate on mbox that are still supported or in development?