Don't send so much, it's almost interminable! (7)
I believe the answer is:
endless
'interminable' is the definition.
(I know that interminable can be written as endless)
'don't send so much it's almost' is the wordplay.
I cannot really understand how this works, but
'it's' could be 'es' ('e' can mean 'electronic' which is similar to 'IT') and 'es' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for endless that I've seen before include "Continuing too long" , "without finishing" , "Continual" , "permanent" , "Going on forever, lacking conclusion" .)