Email::MIME >= 1.923 and < 1.935 would drop too many newlines
in attachments. This would lead to ugly text files without
a proper trailing newline if using quoted-printable, 7bit, or
8bit. Attachments encoded with base64 were not affected.
These versions of Email::MIME are widely available in Debian 8
(Jessie) and even Ubuntu LTS distros so we will need to support
this workaround for a while.