joelsanda says:
I'd like to suggest DailyLit add leading zeros to the installment number (e.g., "Moby Dick (009 of 260)" as that will mean the emails can be sorted by subject in an email client and viewed in correct orders; as well as chronological.

I came across this issue when I didn't get a few installments. When I requested the missing ones they came as expected but I couldn't sort them by subject as the absence of leading zeros creates a sorting problem.