Say it’s not a record mail distribution (8)
I believe the answer is:
disclaim
'say it's not a' is the definition.
I can't tell whether this definition defines the answer.
'record mail distribution' is the wordplay.
'record' becomes 'disc' ('disc' can be a synonym of 'record'**).
'distribution' indicates anagramming the letters.
'mail' anagrammed gives 'laim'.
'disc'+'laim'='DISCLAIM'
Can you help me to learn more?
(Other definitions for disclaim that I've seen before include "Disown or deny, maybe responsibility" , "Deny, refuse to acknowledge" , "Deny or relinquish" , "Renounce" , "Forswear" .)