First of all, it’s crucial to understand the hard and soft bounces, in general, to be able to fully understand reports. If you don’t know what bounces are, please read this – Soft vs Hard bounces.
Let’s assume it’s a report of a campaign you previously sent:
You might think that 75%(OPENED) + 0,33%(NOT DELIVERED) + 25%(NOT OPENED) = 100.33% however, this is not how our system counts.
There are 15000 sent emails. The ‘NOT DELIVERED’ section tells you that 0,33% (50) of your emails bounced. So, the remaining email addresses that are valid are 14950.
For the reports, the number 14950 is used for the mathematics. That means that the open rates are being counted using the number 14950, not 15000. It’s intentional – the user should focus on the real open rates for valid email addresses.
Let’s imagine it’s an another report of a campaign that was sent after the first one to the same subscriber list:
Here the hard bounce emails were removed from the subscriber list, therefore, the list size was reduced from 15000 to 14950.