Names on envelopes potentially also put on notes and notices (10)
I believe the answer is:
addressees
'names on envelopes potentially' is the definition.
I can't tell whether this definition defines the answer.
'put on notes and notices' is the wordplay.
'put on' becomes 'add' (as in adding something on).
'notes' becomes 'res' (more than one re, a musical note).
'and' means one lot of letters go next to another.
'notices' becomes 'sees' (to notice is to observe or see).
'add'+'res'+'sees'='ADDRESSEES'
'also' acts as a link.
Can you help me to learn more?
(Another definition for addressees that I've seen is " Group getting letters".)