In doing some testing with our emails, we sent two emails to our internal team. The two emails were sent to the exact same lists, but the recipient count is different - 157 for one and 100 for the other. What does the "recipient count" mean and why would it be different?
I popped into your account to take a look and I'm seeing 2 mailings from the other day both sent out to 157 recipients.
Perhaps the full numbers for the recipients had yet to update when you checked it.
That being said, in answer to your question, the recipient count that you see on the main Response page is the grant total of addresses that the mailing is being sent out to. If you open the Response data, the overview tab will show you how many of those were delivered and how many bounced.