Qmail compatibility patch

This patch fixes some problems
- qmail don't accept headers devided by CRLF, accepts only LF, other servers should not have problem with it
- boundaries should be devided from headers by additional LF (added \n after Content-Type)
- added Date header to envelope (it ads dependency to intl) - my email client wont work properly without it (Evolution) and some servers can score it as spam

Please test it against other servers - there should not be any problem, but...it seems not easy to comply with all smtp servers