What Is A Good Email Delivery Rate?

Recent delivery rate benchmarks (link and link) released by eMarketer showed that the average is somewhere between 94% and 99%.

ExactTarget writes that 99% seems too high for an average and that 94% seems to low. They suggest that anything below 96% should be investigated further because:

“Permission-based email marketers who send on a regular schedule do not tend to fall below the 96% threshold on a consistent basis.”