The Ideal Sender Score is the average measure from a variety of industries' top senders found in Return Path's Provider Network. The top senders are represented by the very best, 1%-2%, of global IP addresses, which have good infrastructure and deliverability of at least 94%.
Your Ideal is different depending on your volume. Return Path compares ideal low volume senders to other low volume senders. The same is true for high volume senders.