HTML mail Outlook delivery problem

First if someone has template of bulletproof html email for outlook I would be very happy.

Second if someone has a list what trickers spam filter in outlook I would be even more happy (received from, from, content type, return-path, etc).

AND then my case, I'm running out of options here.
I have php mailer, where you can give your name, message, select background image, receivers. It worked just fien with thunderbird and gmail.

But to not to be filtered as spam in Outlook, I needed to add one text line before of my message and one after that message, only text no link nothing. So now the message goes to inbox no matter what the sender is. BUT if I change the second line, for example add one word to it. It will be filtered as spam!!! I am really confused how one text line can tricker the spam filter here!

Any help needed, I can also give the sources of messages if someone want's to take a look. So you can check that only that one little word chanced.

-thanks!

No specs for the outlook junk mail tickers?
Or any validation service?
No ideas at all?

The problem that I tried to describe, is so unbelievable that I just cannot let go..