when submitting, what to do with lack of chapters

So my book doesn't have chapters. It's divided instead by messages ( a la Perks of being a wallflower) When an agent requests your work (let's say synopsis and the first 5 chapters) what should I do? Is there a standard page number that usually is in place of a chapter? So the first 50 pages instead of 5 chapters? My messages are too short to be considered chapter length (about 1-3 pages). I was thinking I would just send the first 30 pages or so and in my email to the agent state something like "as my manuscript is not divided into chapters, please consider the attached first 30 pages." Would this suffice?

when submitting, what to do with lack of chapters