Where did my leads go?

[Nick_Nappo]

As you can see, there was a severe drop in emails sent between the first two emails, and I'm trying to figure out why.

Between these two sends, I sent another email to everyone who was sent the first email but didn't open it.  Did this campaign, then, somehow subtract those people from the second send?

Any ideas would be appreciated.  Thanks!  

[Emily_Thornton1]

It's hard to say without looking at your email send smart campaign and filters. If you are using the same smart campaign to send the email above, is the schedule set so that people can only flow through once? Or, are people hitting communication limits? (A couple common things I would check first).