Exactly according to landlady (2,3,6)
I believe the answer is:
to the letter
'exactly' is the definition.
(I've seen this before)
'according to landlady' is the wordplay.
I cannot quite understand how this works, but
'to' is found in the answer.
'landlady' could be 'letter' (someone who 'lets') and 'letter' is located in the answer.
The remaining letters 'the' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for to the letter that I've seen before include "strictly speaking" , "Literal" , "how should tenant's rent be paid?" , "giving every detail" , "From the tenant, presumably" .)