The mail gem should automatically unwrap format=flowed emails.

RFC 3676 http://www.ietf.org/rfc/rfc3676.txt defines a format=flowed addition to the Content-Type header which acts more like a Content-Encoding header.

It would be great if the mail gem could transparently decode this when asked for the contents of an email body, just as it also decodes quoted-printable etc.

Read RFC 3676 first, focusing on the format=flowed Content-Type behavior and how it affects email body contents. Locate the mail gem's existing body decoding path, including quoted-printable handling, and implement transparent decoding there. Done means callers receive unwrapped body contents for format=flowed emails without changing other decoding behavior.

Written by the indexing model from the issue text.