Difference between -rashii -mitai -ppoi

女性らしい
大人っぽい
大人みたい
All these 3 option have the same meaning, wich is "looks like" , what's the difference in Japanese? i think rashii means the "style", not a single thing but something looks like something else in the complex, but i'm not sure..and difference between mitai and ppoi? i thinks these 2 has the same meaning and ppoi is a more colloqual way to say mitai, but also on this point i'm not sure

http://www.japan-guide.com/forum/quereadisplay.html?0+63661

sorry for double post. the previous thread is about -sou, you, rashii. Mitai is a more casual way of meaning "like", as compared to "you". And "-ppai" is a maybe even more casual way of meaning the same thing? I remember hearing a "sensei-ppai" in an anime before, but otherwise I don't encounter it often.

So there are actually 5 ways of expressing "like" - you, rashii, -sou, mitai, -ppai. It can be rather confusing at the start.

女性らしい = as befits a woman. So you would use this to talk about only women. 女性らしい　しぐさ (gestures that befit a woman, talking about a woman)

大人みたい = as if he/she were an adult. So you would use it only to describe a non-adult.
男みたい　= as if she were a woman. You would say this about a woman who acts like a man.

I agree that "-poi" is a more informal way to say the same as "-mitai" above.
大人っぽい ...would be, for example, a teenager acting as if he/she were a grown-up.
男っぽい ...you would say about a girl/woman acting mannishly.

when talking about someone else, you can use -rashii using the -i adjective stem

kawaii 可愛い(cute)
kawairashii 可愛らしい(she/he/they are cute)

otokorashikunai 男らしくない means "unmanly"

also, no gotoku ~の如く can mean "like"
(from my favorite Seikima2 song)
rouningyou no gotoku
蝋人形の如く
(Tr. like a wax doll)