The mailparser library likes to build HTML strings for attachments. We do not want this for the e-mail app since we handle our presentation separately and one of the big lessons from Thunderbird's libmime was to keep display logic out of MIME parsing logic. This is primarily important from a security and security auditing perspective; we don't want the code present in our builds at all, even if it looks like it should be inert. Assuming the upstream mailparser lib still wants the logic, we should propose factoring it out into a decorating class/pluggable class or something like that.

Firefox OS is not being worked on