Posted Muhammad inside? Outstanding! (7)
I believe the answer is:
salient
'outstanding' is the definition.
(I know that outstanding can be written as salient)
'posted muhammad inside?' is the wordplay.
'posted' becomes 'sent' ('send' can be a synonym of 'post').
'muhammad' becomes 'ali' (I've seen this in another clue).
'inside?' is an insertion indicator.
'sent' going around 'ali' is 'SALIENT'.
(Other definitions for salient that I've seen before include "Conspicuous; pointing outwards" , "Entails (anag) - most important" , "Prominent, striking" , "defence work" , "Projecting outwards; significant" .)