Paperhanger who mails his account? (10)
I believe the answer is:
billposter
'paperhanger who mails his' is the definition.
The definition suggests a singular noun which matches the answer.
'account?' is the wordplay.
I cannot really see how this works, but
'account?' could be 'bill' (billing is a kind of accounting) and 'bill' is found in the answer.
The remaining letters 'poster' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for billposter that I've seen before include "One who pastes up adverts on hoardings" , "One pasting up advertisements" , "One who sticks at his job" .)