module SimpleMailBuilder

See RFC2047 to fully understand how “B” and “Q” encondings work. Basically only ASCII chars are allowed to go unencoded, although they may be encoded. Exceptions are espaces (' '), which can be encoded as underscore ('_') alternatively to the default encoding system described below, and the following chars that must be encoded: '=', '?', '_' and tabs. Encoded chars are represented as '=XX' where XX is the hexadecimal representation in the message charset with 2 digits.